================ The BFG FAQ, Version 2.1, January 22, 1998 =================

Frequently Asked Questions About the BFG9000

By Tony Fabris
http://www.oro.net/~tfabris

Contributors, in alphabetical order:

Doug Bora ....... Content, Editing, Proofing
Tod Bouris ............ Content, Playtesting
Bernd Kreimeier ...... Recent Technical Data
Chris McAllen ......... Content, Playtesting
American McGee ........ Early Technical Data
Randy Pitchford ........ Quake 2 Information
Dean Stretton ..................... Proofing

================================= Disclaimer ================================

This text is intended to give the public information about some elements
of the computer games Doom, Quake, and their sequels, by id Software.
This text was not written by id Software, so bugging them about its
contents is probably a very bad idea.

Additionally, the computer games referenced in the text are of an adult
and graphic nature. In no way is this text intended to promote violence
of any kind. Any references to violence in this text are meant in
relation to the playing of the computer game, not real violence. The
author is adamantly non-violent.

Additionally, this text is being presented in the form of a computer
file. Any illegal or damaging activity related to the use or transfer of
this or any other computer file is not the responsibility of the authors.

=========================== Trademark Information ===========================

All specific names included herein are trademarks and are so
acknowledged: id Software, DOOM, DOOM II, THE ULTIMATE DOOM, QUAKE,
QUAKE 2. Any trademarks not mentioned here are still hypothetically
acknowledged.

============================= Copyright Notice ==============================

This article is Copyright (c) 1998 by Tony Fabris. All rights reserved.

You may make and distribute copies of this work in original form, so long
as the copies are exact and complete, the copies include the copyright
notice in its entirety, and the copies are in electronic form. You may
not charge any sort of a price or fee relating to any copies of this work
in any form.

=========================== Table of Contents ===============================

Preface

Section 0 - Introduction
0A. What is this FAQ about?
0B. How was the information is this FAQ obtained?
0C. How accurate is this information?
0D. Where is the latest version of this and other FAQs?

Section 1 - BFG Basics
1A. What is the BFG9000?
1B. What does 'BFG' mean?
1C. Where can I find the BFG in the game?
1D. What is the cheat code for the BFG?
1E. Why is the BFG missing in my version?
1F. What's this I hear about the original BFG?

Section 2 - The Direct Hit
2A. What is a direct hit?
2B. How much damage does a direct hit do?
2C. What are the limitations of a direct hit?

Section 3 - The Blast Area
3A. What is the blast area?
3B. How much damage does the blast area do?
3C. How long does the blast effect last?
3D. How exactly does the blast area work?
3E. What are the limitations of the blast area?
3F. How many targets can it hit?
3G. How does altitude affect it?
3H. If I am only partially exposed, do I only take partial damage?
3I. What happens if the attacker is fragged before detonation?
3J. What about multiple BFG shots?

Section 4 - Deathmatch Techniques
4A. What is considered unfair when using the BFG?
4B. What is the best way to defend against the BFG in a deathmatch?
4C. What is the best way to attack with the BFG in a deathmatch?
4D. What is the Silent BFG trick?
4E. What is the Level One Strafe trick?

Section 5 - Submitting Corrections
5A. Common misconceptions
5B. I think the FAQ is in error. How do I get it corrected?

Appendix A - Quake Mods
Quake 1 BFG Mods

Appendix B - Quake 2
The Quake 2 BFG10K

=============================================================================

-- Preface ------------------------------------------------------------------

Well, I just got my reply from Bernd Kreimeier, so I think the last few
missing details about the BFG's behavior have finally fallen into place.

He was extremely helpful, and pointed out a couple places in the Doom
public code release that answered my questions. Specifically, we've now
got the exact time delay, damage, and range limitation information.
Thanks, Bernd!

And to add icing to the cake, Randy Pitchford and I have nailed down
the last few details about the Quake 2 BFG10K, so I've fleshed out that
section as well. Thanks, Randy!

This BFG FAQ has been a very unique project for me. Its development
cycle has spanned over two years, and it's been through many revisions.
Thanks to all the folks who e-mailed me about it, and the folks who
contributed.

I think my favorite part of this whole thing was seeing all the other
"Doom specific weapon" FAQ files appear on the net after the BFG FAQ
came out. All the way down to the "Pistol FAQ". The first one, I
recall, was originally intended as a joke... it was a "Rocket Launcher
FAQ" that started out as a satire of the BFG FAQ. It was hilarious,
and even had satires of the ASCII diagrams. Now these files are actual
legitimate FAQs in their own right.

When I first undertook this project, it was simply because I couldn't
get a straight answer to the question, "How does the BFG work" on
usenet. Now it's taken on a life of its own. With the Christmas
release of the Doom source code (Thanks, id!), I guess the whole
thing has come full circle.

It's been a fun ride!

-- Section 0 - Introduction -------------------------------------------------

0A. What is this FAQ about?

A FAQ file, stated simply, is a Frequently Asked Questions file.

This FAQ file describes, in as much detail as possible, the behavior of
the BFG9000 weapon in the MS-DOS version of the games Doom, Doom II, and
The Ultimate Doom. It is not intended to answer general questions about
the game itself. Please refer to the other FAQ files for help in other
areas of the game. You can also frequent the rec.games.computer.doom.*
newsgroups for more information.

We began writing this FAQ out of necessity. We were frustrated at the
apparent inconsistencies in the way the weapon seemed to behave during
game play, especially during deathmatches. There were times when we
would get killed by the weapon when we thought we were completely safe.
Conversely, there were times when we thought we had used the weapon
correctly against an opponent, but they walked away unscathed.

Our intent is to provide players with enough information to attack
effectively with the BFG, and to correctly defend against it in a
deathmatch. Our hope is that this information will give players a new
attitude toward the weapon. We want to transform it from "The weapon we
love to hate" into "The thinking man's weapon".

With the 1997 release of both the Doom source code and the sources for
the Quake 2 game DLL, this FAQ will hopefully provide accurate
information for all versions of this unique weapon.

0B. How was the information in this FAQ obtained?

Initially, the information came from playtesting Doom. We would simply
theorize about the weapon's behavior and then test the theory on the
network.

Testing was performed on Pentium computers running the MS-DOS versions
of Doom II and The Ultimate Doom. Tests were done both in single player
mode and in 4-player deathmatch mode. Testing was performed on the
regular levels as well as custom made levels. In some cases, a special
.WAD file was created to test situations that would be difficult to
reproduce with the regular levels.

At one point early in the development of the FAQ, we exchanged some
emails with American McGee at id Software. He filled in some very
important details for us-- for example, until American told us about
it, we didn't know that the game used a set of damage traces to
calculate blast area damage. His help was invaluable in putting
this FAQ together and getting it off the ground.

Recently, I was able to ask Bernd Kreimeier some specific questions
about the code. His answers, I hope, have cleared up any ambiguities
in the details.

0C. How accurate is this information?

Fairly accurate. Accurate enough to base your playing strategies on.
However, it has not been tested with every single version of Doom, and
there may be differences among platforms.

Then there's the issue of the Doom public code release. That code was
"cleaned up" by Bernd Kreimeier, who was given the sources by id
Software to prepare it for a public release. Bernd tells me that he
did not change the BFG code in the cleanup process, but the sources
are from a later date than the original commercial releases of Doom
and Doom 2. In his words:

It is the January 10th, 1997 version - a few TNT/Plutonia mod's have
been done in this code base, but I am in no position to confirm
whether this affected the BFG code. I never looked at that part
of the code, nor changed it.

Until I hear otherwise, I'm going to assume that the public code release
contains the same BFG behavior as the commercial releases. Everything
you see in this FAQ will be based on the old playtesting we did in 1995,
cross-referenced against the sources found in the 1997 public code
release.

Finally, now that the folks are modifying, compiling, and releasing
their own versions of Doom, who knows what they might change? The BFG
was an infamous feature in Doom, and will likely be the first target
for modifications. So read those README.TXT files before you play
a modified Doom.

Despite all of that, some items in this file may still be conjecture.
Please see section 5 if you suspect this FAQ contains erroneous
information.

0D. Where is the latest version of this and other FAQs?

The latest Doom-related FAQ files and other documents can be found at
all of the Doom mirror FTP sites. The central location for the Doom
mirrors is at ftp.cdrom.com. However, that site is usually quite busy,
and you may need to locate another mirror site from which to download.
Listing all the mirror sites is beyond the scope of this document.
See the 'DOOM: Rec.Games.Computer.Doom FAQ' or 'DOOM: FTP and WWW
Sites' postings in the rec.games.computer.doom.* newsgroups for a
complete list.

The URL of the directory that contains the Doom FAQ files (usually in
TXT format, compressed in a ZIP file) is:

ftp://ftp.cdrom.com/pub/idgames/docs/faqs/

The latest official version of the BFG FAQ is also posted monthly to
the rec.games.computer.doom.announce and .playing newsgroups. This is
part of the RGCD Periodic Information Postings (PIPs). If your news
server does not keep the articles long enough for you to find one of
the PIPs, they are archived at:

ftp://ftp.cdrom.com/pub/idgames/docs/rgcd-pips/

The official location for the hypertext version of the BFG FAQ is
DoomGate on the World Wide Web. Check it out here, along with some
other good documents:

http://doomgate.gamers.org/docs/


-- Section 1 - BFG Basics --------------------------------------------------

1A. What is the BFG9000?

The BFG9000 (or BFG) is arguably the most powerful weapon in the computer
games Doom, Doom II, and The Ultimate Doom. It is also the most difficult
weapon to use well in a deathmatch (multi-player competition), because it
does not behave in a simple 'point and shoot' fashion.

When you have it in your arsenal, the BFG is selected by pressing the 7
key on your keyboard.

When you pull the trigger, there is an excruciatingly long pause as the
weapon warms up. Then a large green ball of plasma is emitted from its
barrel. The plasma ball flies in the direction you fired it until it hits
a target or a wall. Like all weapons in Doom, it will fly straight
through decorative objects like torches or trees.

When the green ball hits a solid object, it detonates and does two types
of damage: Direct Hit and Blast Area. Each damage type is outlined in
its own section, later in the FAQ.

1B. What does 'BFG' mean?

The general consensus is that BFG stands for Big Fragging Gun. Well,
that's the G-rated version at least. Hank Leukart's Official Doom FAQ
(the one that ships with the game) says so.

So is "Fragging" a deliberate softening of another famous F-word? Maybe.
But the term "frag" is an actual word, and it's used in Doom to
represent a confirmed kill in a deathmatch game. This comes from the
idea that in a deathmatch, you are killing your fellow space marines.
The definition of frag is:

frag Slang. Verb, transitive
fragged, fragging, frags
To wound or kill (a fellow soldier) by throwing
a grenade or similar explosive at the victim.

That's not to say that the the word Frag isn't often interchangeable
with the other word. And, of course, the Quake 2 manual calls the new
BFG10K the "Big, uh, freakin' gun."

Other good name suggestions that have found their way to the authors
are "Big Funny Gun" (Chris Somers) and the much more logical "Blast
Field Gun" (William D. Whitaker). I'm sure there are thousands of names
you could invent for it...

1C. Where can I find the BFG in the game?

Listing all the locations that the BFG can be found is beyond the scope
of this document. For detailed information on the location of all
weapons, please consult the other FAQ files. Keep in mind that the BFG
appears more often in deathmatch games than it does in single-player
games.

1D. What is the cheat code for the BFG?

While you are playing the game, type the keys IDKFA to give your marine
all weapons, keys, and ammunition. Then press the 7 key to select the
BFG.

Note: This cheat code is disabled in multi-player games and single-
player nightmare-skill games.

1E. Why is the BFG missing in my version?

If you perform the above cheat correctly, but do not get the BFG, you
may be playing the shareware version of Doom. You must purchase the
commercial version of Doom from a retailer or id Software before the
BFG can glorify your screen.

1F. What's this I hear about the original BFG?

The current version of the BFG is not the way id's designers
originally envisioned it. The BFG behaved quite differently in a
pre-beta release of Doom.

It worked by shooting multiple streams of different types of plasma
and fireballs. Because this required an unusually large number of
moving objects, it tended to slow down the game. Therefore, the BFG
was redesigned with the invisible blast area that is used today.

Recently, these early Doom versions have been distributed on the
internet. You can find screen shots and downloads at:

http://www.classicgaming.com/doom

If you want to download the one with the special BFG, get the
October 4th, 1993 press-release version.

-- Section 2 - The Direct Hit ----------------------------------------------

2A. What is a direct hit?

A direct hit happens when the BFG's green plasma ball directly hits
a target. The target can be a monster, an exploding barrel, or an
opposing player in a multi-player game.

2B. How much damage does a direct hit do?

A direct hit with the BFG causes a random amount of damage between
100 and 800 points, in 100-point increments.

The base damage value for the green ball is 100 points, which gets
run through the missile damage randomization routine:

damage = ((P_Random()%8)+1)*tmthing->info->damage;

Note that the above code results in damage values in 100-point
increments, i.e., 600 or 700, but not 666.

A note about skill levels: Testing seems to show that weapons always
do the same amount of damage to monsters, but that the player objects
can absorb the weapons better at lower skill levels. Therefore, it
takes more shots to kill a player at lower skill levels, and fewer
shots at higher skill levels. This is why some players prefer to
deathmatch at the higher skill levels: The frags are quicker that way.

The Doom public code release bears this out. They perform a right
bitshift (a fast way to divide an integer by two) on the damage value
as follows:

player = target->player;
if (player && gameskill == sk_baby)
damage >>= 1; // take half damage in trainer mode

And of course, armor is a factor as well. Depending on the type
and the amount of armor worn by a player, some armor will be
subtracted in lieu of health.

If your target is lucky enough to survive a direct hit, he is still
susceptible to damage from the blast area. This happens sometimes in a
deathmatch. Since there is a brief pause between the direct hit and
the blast area calculation, your victim may go through several stages
of fear and elation in the space of one second:

1) Victim sees the BFG coming towards him (Uh-oh.)
2) BFG scores a direct hit (D'oh!)
3) Victim realizes he has miraculously survived (Woo-Hoo!)
4) The flash damage kills him a moment later (D'oh!)

2C. What are the limitations of a direct hit?

The direct hit is not limited by the same parameters as the blast area.
There is no range limit, and the damage does not decrease with distance.

The hard part is that the BFG's plasma ball travels at a fixed speed,
and can be avoided by an alert deathmatch player. The reference number
for the BFG ball's speed, as stored in the .EXE file, is 25. For
comparison, rockets travel at 20 and plasma gun shots travel at 25.

If it seems like this is too fast, and would not be easy to avoid,
remember that the plasma gun fires in a continuous stream. The BFG can
only be fired once every few seconds. The BFG's green ball is also very
bright and large on the screen. All of those factors make it generally
easier to avoid in a deathmatch game.

A direct hit in a deathmatch (against good players) is usually the
result of luck, or the result of a player that did not know the BFG ball
was coming towards him. See section 4 for details of a trick that can
help you achieve the latter scenario.

The direct hit can only damage one target. If there are two targets
very close together, the green ball can only hit one of them directly-
whichever one it touches first.

-- Section 3 - The Blast Area ----------------------------------------------

3A. What is the blast area?

After the green plasma ball detonates, and after the damage is calculated
and deducted from the target that received the direct hit (if any), the
area effect of the BFG is calculated. Targets that fall within a
specially defined area will take varying amounts of damage.

Simply put, the blast area is like an imaginary 'cone' or 'fan' of damage
traces that briefly extends outward from the attacking player. The cone
always points in the direction that the weapon was fired. For instance,
if you originally fired the weapon in the northwest direction, the cone
will always face northwest, regardless of which direction you're facing at
the moment of detonation.

Note that this does not mean that the attacker must continue to face in
that direction. The attacker is free to turn away from his targets, as
long as he moves to a position that keeps this imaginary cone pointed at
them. Common misconceptions are that you must be facing either the targets,
the detonation point, or the same direction as the weapon was fired. None
of those things are necessary in order to inflict damage.

Also note that this imaginary cone has no relation whatsoever to the
detonation point. The location of the detonation point is only important
for the direct hit (see section 2). Only the moment of detonation is
important, not the location. It is possible to have the green ball
detonate twenty miles away in a completely different room at a totally
different altitude, but the blast can still cause damage right next to
you.

The paragraphs above cover the basic concepts of the blast area. More
detailed information can be found in section 3D, below.

3B. How much damage does the blast area do?

Since the Doom public code release, I'm revising this section.
Originally, we were told that there were 20 traces, each doing a
random amount of damage between 5 and 15 points. But now that I look
at the public code release, it's telling me a different story. I've
confirmed this with Bernd. The function "A_BFGSpray" is pretty simple,
and here's how it works:

There are 40 traces, and each one does 1-8 random points of damage in
a 16-iteration loop. Meaning each trace will do between 16 and 128
points of damage.

Because these traces radiate outward from the attacker in a fan shape,
a target will more likely be hit by a given trace if he is close to
the attacker. Therefore, targets closer to the attacker will generally
take more damage because they are hit by more traces.

If a target is very close to the attacker (for instance, standing right
next to him), the target might be within the hit range of all the
traces. The amount of blast area damage in this situation would be
between 640 and 5120 points. However, all traces would not necessarily
be absorbed by that target, and might move on to other targets. See
section 3F, below, for more information on this phenomenon.

A note about random numbers:

A phenomenon known as the 'bell curve' happens when you combine the
outcome of multiple random numbers. Players of book-and-paper role-
playing games may recognize it. In those games, you would often use
three dice to generate a random statistic. In theory, adding the three
dice would generate a random number between 3 and 18. But in reality,
the actual results would be weighted towards the middle of the range,
around eleven. The odds of getting a three or an eighteen are rare
because you'd have to roll 1+1+1 or 6+6+6. There's only one possible
combination for each outcome. On the other hand, rolling an eleven is
relatively easy: 6+4+1, 5+5+1, 3+3+5, etc. If you were to graph the
outcome of a thousand rolls, the graph would be shaped like an arc or
a bell, with more rolls coming up in the middle of the range of
possible values. Hence the name 'bell curve'. The role-playing games
use this to make certain random statistics more fair.

This applies to the damage traces, as well, because they are
essentially a group of multiple random numbers. For instance,
although the possible damage for a single trace is 16-128, the
odds are that the total damage from a trace will more likely be
around 50-60 points, due to the bell curve. The odds of doing
full or minimum damage in that situation would be extremely rare.

Actually, if you look at the Doom code, you'll find that even the
random numbers aren't random. They're "pseudo-random", and for a very
good reason: So that all four computers in a multiplayer game can be
synchronized. They pull the random numbers from a table whose index
changes each time it's accessed. Looking at the table, it's obvious
that there are no "runs" of all low or high numbers, so it's not only
unlikely that full or minimum damage would be done, it's actually
impossible in the current code.

3C. How long does the blast effect last?

The blast effect is instantaneous, but it does not activate until
the "S_BFGLAND4" frame plays. This can be seen in the source code
in the frame/action pointer table in "info.c".

What this means is that the "A_BFGSpray" function is triggered 16
game tics after the first death frame of the direct hit was
started. Assuming a game tic is 35 frames per second, then the
blast effect is calculated 0.4571428571429 seconds after the
detonation. Which, Captain, if I had any emotions, I'd be excited
about.

But what about the other thing?

Oh, you mean, when someone is running out from from behind a corner,
and it looks like the blast area should have missed them, but it got
them anyway? How can that be? They ran out from behind the corner
after the blast area was calculated!

Well, it's been a while (two years) since I LAN-playtested this
phenomenon. We were never able to nail it down under controlled
tests. The "A_BFGSpray" function calculates completely within a
single game tic, and if there's a slow computer in the game, all
of the computers will freeze until the slow computer is done with
its blast area calculations.

The only thing I can figure is, the guy's radius (which is larger
than his visible sprite) was within sight of the damage traces.
He took damage while he still seemed to be behind the corner, even
though he wasn't. More on this phenomenon below.

3D. How exactly does the blast area work?

The blast area is a spread of invisible traces that radiate outward
from the attacking player. The damage for the traces is calculated
shortly after the green ball detonates against a target or a wall.

Here's the code for the function in the public code release. I've
waited two years to see this:

void A_BFGSpray (mobj_t* mo)
{
int i;
int j;
int damage;
angle_t an;

// offset angles from its attack angle
for (i=0 ; i<40 ; i++)
{
an = mo->angle - ANG90/2 + ANG90/40*i;

// mo->target is the originator (player)
// of the missile
P_AimLineAttack (mo->target, an, 16*64*FRACUNIT);

if (!linetarget)
continue;

P_SpawnMobj (linetarget->x,
linetarget->y,
linetarget->z + (linetarget->height>>2),
MT_EXTRABFG);

damage = 0;
for (j=0;j<15;j++)
damage += (P_Random()&7) + 1;

P_DamageMobj (linetarget, mo->target,mo->target, damage);
}
}


The traces radiate outward in an imaginary cone that is 90 degrees
wide. This is, coincidentally, about the same width as the player's
field of view.

Because the code uses "mo->angle" as the source for its angle, the
cone always points the same direction that the green ball flew. For
instance, if you fire the green ball in the southeast direction, your
cone of traces will always radiate towards the southeast.

However, because it uses "mo->target" as the source for its attacks,
the traces radiate from where the player is standing, not from the
green ball.

So...

Regardless of how much you run and turn between the time you fire and
the time the green ball detonates, the traces will always radiate from
your location. Think of it like a tank with a gyroscopically stabilized
turret: only the cone's origin point moves around with you, not its
direction. The cone's direction remains fixed on the same compass
heading.

From a technical point of view, the game engine does not actually keep
track of the cone while you're running around. That's just the effect
it seems to have. It simply uses the green ball's vector as the source
angle for the traces, and the player's current position as the source
location.

Note that the vector of the green ball's flight is based on what
direction you were facing when the ball leaves the barrel of the gun,
not when you pulled the trigger.

Here's a diagram of how it works:

* <- Blast
detonates \ Damage /
here \ Cone /
\ /
^ \ /
| \ /
| \ /
X X --> X
Attacker Attacker Attacker
fires BFG runs east is here at
northward detonation


Note that this diagram is foreshortened. The detonation point would
have to be quite far away in order for the attacker to be able to run
that far. But the principle is the same, regardless of how far the
green ball flies: The damage cone is calculated after the green ball
detonates.

When the green ball detonates, the traces are calculated one at a
time, using the same criteria for calculation that the engine might
use for a bullet: If there is a solid object (a wall, etc.) between
the target and the attacker, the trace is harmlessly absorbed by the
object. With one exception: In order to hit a target with a bullet,
you had to be facing the target. You don't have to be facing your
target in order to do damage with one of the traces.

Quick review:

- The cone of traces always points in the same compass direction, the
direction you originally fired the BFG.

- You sort of 'carry the cone around' with you as long as the green
ball is still flying.

- When the green ball detonates, the cone of traces does its damage
depending on where you're standing at that moment, and who is in
the cone.

- You do not have to be facing the targets to do damage, you only
have to maneuver into a position where the cone is pointing at your
targets.

3E. What are the limitations of the blast area?

Revision time. It seems as though there is a hard limit on the
range. Bernd says he thinks this line:

P_AimLineAttack (mo->target, an, 16*64*FRACUNIT);

actually limits the traces to within 1024 (16*64) game units.
It's been a while since I playtested this, so I don't remember if
I was ever able to register a hit when outside of this range.

Whether it actually limits the range or not, outside that range
it would become increasingly hard to get a single trace to land
on a given target anyway. So just deathmatch under the assumption
that you can't hit anyone outside 1000 units.

If you are unfamiliar with the Doom engine's units, remember that a
standard teleporter pad is 64 units across. Line up 16 of those and
you've got a basic idea of what 1024 units is.

The blast damage is also limited to targets that have an unblocked line
of sight to the attacking player. This does not mean the attacker must
face the target. It means that the attacker must be in a position where
his traces can see the target, i.e., he could see the target if he were
facing in that direction.

3F. How many targets can it hit?

The blast area can only hit as many targets as its traces can touch.

Originally, we stated that one trace can damage more than one target.
This was because we did tests where a single shot killed 25 imps. But
that was back when we thought there were only 20 traces. Now that we
know there's 40 traces, it seems as though the number of objects that
can possibly take damage is 40.

Of course, in regular game play, rarely are that many targets standing
in such a perfectly aligned pattern. Usually, some individual targets
will soak up more than one trace, while other traces miss targets
completely.

The traces are calculated on a 'first come, first fragged' basis. For
each trace, the damage is calculated and subtracted from the target,
and the target dies if there's enough damage. Then the engine moves
on to the next trace.

Here is how it works:

(Please note: In the discussion below, we refer to 'line of sight'
loosely. Remember that the attacker does not need to be facing his
targets to inflict damage.)

In the following scenario, imagine that the attacker is standing in a
direct line with several targets (imps, perhaps) lined up in front of
him, and the green ball detonates on a wall somewhere:


Attacker: X-> X X X X X X X Detonation point: X
(Imps)

The first couple of imps are close to the attacker. They crumble, having
soaked up some of the traces that are pointing ahead of the attacker.
The next few imps are a little further away, and absorb some more of the
traces, but not as many. They absorb fewer traces for two reasons:
1) because the imps in front of them absorbed some of them
already, and
2) because they are farther away and the traces are more
spread out.
But they still die. The next imp gets damaged, but does not die. He has
soaked up the last trace that was headed in that general direction. The
last imp is not damaged at all because there are no more traces left in
his direction.

In order for the above scenario to work, the targets must be perfectly
aligned. For instance, in the following scenario, all of the targets take
full damage, because there's no one in front of them to soak up traces.

X
Attacker: X-> X Detonation point: X
X Y

The one target in the back (Y) is still susceptible because it is not
blocked by another target. The attacker can see him through the gap. So,
for example, an imp standing directly behind a cyberdemon is fairly safe,
but an imp standing next to a cyberdemon is a sitting duck.

The moral to this story is: In deathmatch, do not depend upon other
players or monsters to absorb the BFG blast unless they are exactly
between you and your attacker. And you'd better hope they're very
healthy. In all other cases you take full damage.

3G. How does altitude affect it?

For the most part, it does not. With a few exceptions.

Again, in the discussions that follow, we refer to 'line of sight'
loosely. You do not have to face your targets to hit them.

If a difference in altitude brings your target out of the sight of your
traces, then yes, it makes him safe from the blast damage. But if your
traces can see any part of him, he takes full damage regardless of how
much higher or lower you are than he is.

As far as altitude is concerned, the traces seem to use the same
criteria as your view does to determine if the target is visible. In
other words, if both you and the damage cone are facing the target, but
the target is above the top of the screen, you can't hit him.

But there is a catch. The upper and lower angle limit of the traces
seems to be the same as your view would be if your screen was fully
zoomed in. For instance, if you are displaying the status bar at the
bottom of the screen, your view window is slightly cut off at the top
and bottom. Press the plus (+) key repeatedly to zoom all the way in,
and you can see what this means. The BFG's traces seem to use the same
angle as this full view does to determine if they can hit the target.
So if you've got the status bar showing, you can actually hit someone
who is off the top of your screen. If you are fully zoomed in, your
view seems to be an accurate representation of the damage cone's angle.

Note: The angle limit of the traces is not affected by changing your
zoom level. The traces use the same angle regardless of what your zoom
is. It's just that zooming all the way in changes your screen's
aspect ratio. So you can see more stuff at the top and bottom of the
screen, stuff that normally would have been hidden behind the status
bar.

If you are standing on a ledge above your target, and you are so close
that you can 'touch' him (i.e., you can't step off the ledge because
you're bumping into him), your shots will go right over his head and
the blast damage will not affect him. This is because, technically, the
traces can't see him. Well, if you could look down you would see him,
but you can't look down in Doom. Must be those darned restrictive space
helmets.

3H. If I am only partially exposed, do I only take partial damage?

No such luck. The only thing that reduces your damage is getting hit
with fewer traces. Here is how it works:

If you are hiding behind a decorative sprite (such as a tree or a
technical column) you are fully exposed. All weapons in Doom always
pass completely through decorative sprites.

If you are peeking over a podium, or partially obscured by a raising
lift, or a closing door, and only half or one-tenth of you is showing,
you still take the full amount of damage. The traces are calculated
based on the game's two-dimensional block map. As far as the game
engine is concerned, all of the traces can still hit you.

If you are hiding behind a vertical wall with your rear end peeking
out, I'm pretty sure you still take full damage because the traces
auto-aim at you. Tests seem to show that your distance from the
attacker is more important than how much of you is exposed.

Also remember that what counts as 'showing' may not be what you think.
The Doom engine uses the radius of the player to determine visibility.
Your player's aspect ratio does not change when you rotate. It also
seems as though your radius is slightly larger (in some cases) than
the sprite (picture) that represents your player. In tests, it is
possible to inflict damage upon a player that seems to be out of sight
(no visible pixels) but whose radius is large enough to count as
'visible' to the BFG traces.

3I. What happens if the attacker is fragged before detonation?

The BFG's traces are still active, even if the attacking player is
dead. So if you fire the BFG, then get fragged, do not press the space
bar to respawn your marine right away. Wait until the green ball has
detonated before you respawn.

Here's why:

Even after being fragged, you can still see the action from your fixed
point of view on the ground (your 'dead' state). The traces remain
active and can still frag an opposing player (hopefully the one that
fragged you). The traces will radiate from your dead body's 'eyes'.
The traces still follow the same rules, i.e., they radiate in the
direction the green ball was fired, regardless of which direction your
'dead view' is facing.

In a previous version of this FAQ, we reported that you will lose
the chance to frag your opponent if you respawn before detonation.
Several people pointed out to the authors that the statement was in
error. The traces remain active even after respawning. Testing shows
that the traces do, in fact, continue to radiate from the dead body
even after you have respawned in a completely different area of the
map. This testing was performed at the prompting of Kirby Nixon, who
insisted that it was true. Whaddya know? He was right.

This means that, technically, you don't need to hang around and watch
your opponent in order for the traces to work. But Kirby pointed out
a good reason to wait for the detonation before respawning: Your dead
body's traces can frag you, too! Just because they were once your
traces doesn't mean you're immune. If you are unlucky enough to
respawn within your dead body's damage cone, you can kiss your butt
goodbye.

Of course, the same thing applies to projectile weapons like the
rockets and plasma. If you play enough deathmatch, you've probably
been fragged by your own rocket a few times. Don't be embarrassed,
it happens to the best of us...

Please note: Any projectile kills made by a respawned player (whether
by rockets, plasma, BFG traces, etc.) do not contribute to that
player's frag count. Killing -yourself- in this manner does not change
your frag count, either. This appears to be because the game engine
creates a new instance of the player-object at respawn-time, and
therefore 'forgets' to award that frag. In any case, if you wait
before respawning, you will get credit for the frag as long as you're
still dead. This is another reason to wait for detonation before
respawning. Special thanks to John Castelli for pointing this one out.

3J. What about multiple BFG shots?

Each BFG shot is tracked and calculated independently. The game
engine's code is object-oriented, and has no trouble keeping track of
multiple blast areas. Each damage cone's direction is based on the
direction of its corresponding green ball.

The origin point of the damage cone is based on the current location
of the marine who fired it (even if that marine is just a dead body-
see section 3I for more info).

-- Section 4 - Deathmatch Techniques ---------------------------------------

4A. What is considered unfair when using the BFG?

Many deathmatch players moan and groan when the BFG is used successfully
against them. 'What a cheap frag, you craven coward!' they shout. Well,
they usually use fewer words to express the idea, but that's what they
mean. This is usually due to a lack of understanding about how the weapon
works.

The purpose of this FAQ is to educate players about how the BFG behaves.
If you know how it works, you will know how to defend yourself against
it. You will also know how to effectively attack with it. If both (or
all four) players have the same knowledge about how the weapon
functions, then the BFG by definition is not unfair. If you play against
an opponent who does not know how the BFG works, then you should make
sure to educate them on its behavior before turning them into paste.

Having said that, the following things are debatable regarding fairness.
I'm not saying they are patently unfair, I'm just saying that their
fairness is debatable:

- The Silent BFG trick (see section 4D).

- 'Camping on' or 'guarding' the BFG when you are playing deathmatch
2.0, and picking it up again every time it reappears.

- Having a BFG left over from a previous level when there is no BFG
available to the other players on the current level.

In the last two examples, four-player deathmatch tends to cancel out
any advantages to those techniques. The remaining three players usually
coordinate and attempt to bring down the king of the hill in these
situations.

4B. What is the best way to defend against the BFG in a deathmatch?

AVOID THE DIRECT HIT, AND GET OUT OF THE CONE OF DAMAGE.

(OK, so it ain't Rocket Science.)

This requires, of course, that you know where the cone of damage
actually is. That, in turn, requires that you know where your attacker
is and in what direction he fired the weapon. That, in turn, requires
that you know the weapon was even fired at all. Which, in turn, may be
difficult against a player who has mastered the Silent BFG trick
(See section 4D).

It still helps if you are playing the game with a stereo sound card
and headphones. This allows you to hear how far away and in which
direction your opponents are. If you think in three dimensions, the
sounds you hear in the game will give you a great tactical advantage.

You must understand completely how the weapon works before any
avoidance technique would be meaningful. So if you skipped ahead to
this section, go back and read the gory details.

With all that said, here are a few ideas. These are just things to
try, not necessarily good things in all cases.

- Run past the attacking player so that you end up behind him. This
assumes that he is still facing the same direction as his damage
cone. You will be completely safe if you're on the opposite side of
his cone. This can backfire if you're not careful. You could end up
three feet from him and inside his cone when the green ball
detonates, and soak up some rays. That SPF 60 sun block won't help,
either.

- If you think you're about 1000 units away from the attacker, and you
don't think he's running towards you too fast, you can try running
away, and hope that the traces will be too thinned out to damage you
seriously.

- You can duck behind a nearby wall or a solid column. If you can see
your attacker, simply move so the column is between you and him.
Wait for the blast to detonate and die down, then step out from the
column and place some ordnance in his face. This technique works
well on Doom II's 'Circle of Death' level (11).

- If you are very close to him, you can attempt to frag him before his
shot gets off. When he pulls the trigger, there is a slight pause
while the weapon warms up where you can still stop him dead in his
tracks. There is nothing more exhilarating than hearing his BFG
spinning up, then the sound of his scream as your super shotgun
removes his face. Muahahahaha...

- If you are involved in a turning, running, spinning melee in an open
area, keep it up. Learn how to circle-strafe (use a combination of
mouse and keyboard controls to turn, run, and strafe all at the same
time). If you keep your attacker running in circles, his cone of
damage will hardly ever be pointing at you. He will eventually run
out of ammo, or you will frag him with conventional firepower. This
technique works well in the main courtyard of Doom II's 'Citadel'
level (19). In this kind of melee, it is nearly impossible to keep
track of the cone (for either you or your attacker), so you are
really taking a gamble that the turning fight will be to your
advantage. But the exhilaration of winning that kind of fight is one
of the best rushes you can get.

- If you are well armed and very healthy, you can judge whether or not
you can survive a blast area hit at your current distance. Then take
advantage of the fact that he's trying to keep you in his sight. He's
got a moment or two where he must leave himself exposed while he
tries to soak you with his traces. Pepper him with rockets or plasma.
Grit your teeth and take the blast area hit, but keep on him. Just
don't get too close.

- Stephen "Blue" Heaslip says this in his Doom Deathmatch Strategy
Guide (referring to an earlier release of this FAQ): "A point about
BFG defense not covered in the BFG FAQ is the preemptive strike.
The best BFG defense in an AltDeath game is to repeatedly pick up
the BFG so your opponent can't. The best BFG defense in a
deathmatch 1.0 game is to kill your opponent before he gets it."
Thanks, Blue. I never mentioned this one in earlier versions of the
FAQ because I thought it was obvious. But you're right, of course.
The best defense is a good offense.

- Anything else that takes advantage of the particular quirks of the
weapon. Remember that you can use your knowledge of BFG attacking
techniques to your advantage, like the examples above.

4C. What is the best way to attack with the BFG in a deathmatch?

KEEP YOUR TARGETS IN THE CONE OF DAMAGE.

(You were expecting some deep revelation, or what?)

This requires, of course, that you know where the cone of damage
actually is. So if you looked here first, go back and check out
the rest of this FAQ for details.

Anyway, here's some ideas. Not necessarily comprehensive:

- The best universally accepted method is to shoot a wall or solid
column that is very close to you. In this situation, your cone of
damage roughly equals the visible targets on the screen. This is
because you don't have much time to move around before detonation.
Your targets don't have much time, either (You will notice that
all of the 'defense' tips in this FAQ assume having time to react).
Because we already know two things:
1) The direct hit is difficult to achieve,
2) The location of the detonation does not matter,
there is no reason to try shooting the green ball at your targets.
Your goal is to get the green ball to detonate as quickly as
possible after you decide upon your targets. Just make sure you're
facing your targets when you fire. If you have to rotate away from
the direction of fire in order to see your targets, your cone of
damage may not hit them.

- The next best thing is to use the strafe feature heavily. Don't
rotate, just keep strafing and keep your targets in sight while you
wait for the detonation. This also keeps your cone of damage roughly
lined up with your view, allowing you to use your view as a
reference. If your targets are trying to run behind you to get behind
your damage cone, running backwards while strafing may also help.

- Combine the two previous attack methods: Shoot a nearby wall, then
strafe toward your targets. This takes advantage of the pause that
happens after detonation. You have a few heartbeats before the traces
are calculated, so use this time to strafe your targets into view.
The best example would be at a 90 degree hallway intersection: Shoot
the wall at the corner, then strafe out into the hall. This is really
just a shortened version of the level one strafe trick, except you
don't have to wait for detonation.

- "Everything I need to know, I learned at Top Gun." Avoid turning
fights. See the related item under the defense techniques, above.

- "Keep your friends close, but keep your enemies closer." Really.
The closer you are, the more traces will hit their faces. Don't
even bother firing if your opponents are more than 1000 units
away: you will either miss, or do very little damage.

- Don't be afraid to use it in close quarters. You might think the BFG
is designed for open-area use, but it actually works best when things
get cramped. The 'shoot the wall' trick really mulches 'em in a
narrow hallway.

- Keep it loaded, then use it liberally. Find lots of ammo for it. Use
a backpack to double your ammo capacity. Then shoot it off whenever
you get the urge. For instance, every time you enter a new room or
open a door.

- Set up pre-timed shots that take advantage of its long warm-up time.
Like this: pull the trigger, -then- open the door. Or pull the
trigger, -then- drop off the ledge into the room with your target.

- Shoot the green ball at a very distant wall (such as outdoors or
down a long hallway), then run into the room where your target is.
He may not know you even fired, or he may think it already detonated.
Either way, you can just stand there. When the ball eventually
detonates, your target will simply see himself crumble to the ground,
realizing too late that you were standing still because you were
keeping your traces on him. See section 4E for an example of this.

- Use 'combo' moves. Use the above 'distant wall' technique, but switch
to a conventional weapon as you run into the room. Your traces still
work, even if you have switched weapons. Blast 'em with both the BFG
traces and something else at the same time. Special thanks to Dan
Christensen for this suggestion.

- Bait your prey. Use the above 'distant wall' technique, but switch to
the pistol and fire it while running into the room. They will hear
your pistol and attempt to get very close to frag you. If timed
correctly, they will be right in your face at detonation time. Splat
city.

4D. What is the Silent BFG trick?

Defending yourself against the BFG pretty much depends on your ability
to know precisely when it is being used against you.

If you are fortunate enough to play deathmatch with a stereo sound card
and headphones, you know that sound cues are vital to playing well in
deathmatch. In many cases, the only way a potential victim knows the
green ball is in the air is by the distinctive sound the weapon makes
when fired. The headphones can give him directional cues as to its
origin, and therefore point the way towards a proper escape.

So if you wish to get the drop on someone, wouldn't it be great if you
could put a silencer on that weapon? Well you can. A limitation in
Doom's sound code allows you to silence the firing sound of the BFG.
Regardless of the 'Number of Sound FX to Mix' that you chose in Doom's
setup program, your character can actually only utter one sound at a
time. This includes all weapons firing. If you cause your character to
grunt, i.e., you jump off of a ledge or press the space bar on a blank
wall, you have a brief period while the grunting sound is being played
in which you can pull the trigger and no sound will be emitted from the
weapon. Your grunt makes a little noise, but it's relatively quiet and
is sometimes ignored by your opponents.

I've seen other information that tells me I've got it backwards:
That you're supposed to fire first, -then- grunt. I don't know
which is correct. Try both and use whichever one works for you.

While it works well in theory, in practice the trick is hard to
perform. It also may be a little unfair. As with all secrets, it
definitely makes the game unfair if you don't share this information
with your opponents.

As of this writing, there seems to be a small handful of players on
the doom newsgroups who use this trick. The first person to submit
this trick to the author of this document was John Fedor.

Interesting anecdote: When reviewing a draft copy of this FAQ,
American McGee at id Software informed us that they have been using
the Silent BFG trick in their deathmatch games since day one.

4E. What is the Level One Strafe trick?

The level one strafe trick is not a deathmatch technique per se, but
it's a demonstration of the BFG behavior that educates many folks on
how the BFG really works. The act of performing this trick tends to
open one's eyes to the amazing possibilities of the weapon. It also
proves some points made in this FAQ.

Doug Bora first pointed this demo out to our particular group. Credit
for the original version of this demo goes to John Ripley of the UK.
The full deathmatch demo file PETALK2.ZIP is the first example of this
specific action. Since that time, this has been repeated by many folks
on the Doom newsgroups.

PETALK2.ZIP should be available at:

ftp://{INS site}/lmps/doom2/1.9/petalk2.zip
where {INS site} = any DOOM ftp site, eg. ftp.cdrom.com/pub/idgames

How to do this:

- Set up a deathmatch game with Doom II, starting on level one, no
monsters, deathmatch 2.0, ultra violence skill level.

- Player one (Green) will most likely appear on the ledge with the
chainsaw, BFG, rocket launcher, and super shotgun. Tell him to move
so that he is within view of that first entrance room, standing on
the ledge where he can see down the brightly lit hallway from his
perch above the brown room. He can either stand up on the starting
ledge, or hop down into that first brown room. Either way, it will
work. Tell him to sit tight right there. He is frag bait for this
demonstration.

- Player two (whoever) will stroll into the brown room and pick up
the BFG behind the column. Wave to the nice guinea pig waiting
patiently for you. (Hi Phil. Hi Ralph.)

- Player two strolls down the brightly lit hallway to the intersection
where he can see the other dark room, way down the long hallway. You
can just make out the plasma gun sitting on that podium in there.

- While facing the plasma gun from the intersection in the bright
hallway, fire the BFG. When the shot actually leaves the barrel of
the gun and begins traveling toward the plasma gun, strafe quickly
back toward the intersection where you can see Greenie standing
in the first brown room.

- If you reached that hallway intersection in time (before the green
ball detonated in the plasma gun room) you will be rewarded with
seeing the frag bait get fragged. Well, at least damaged. Maybe
fragged.

- One extra credit point to anyone who guessed that you don't have to
be facing Green Boy to kill him. You just have to make it to that
intersection in time. You could be turned completely away from him,
he will still be hit by the traces. You can prove this by running
straight to the intersection rather than strafing to it.


This demonstration proves the following:

- You don't have to be anywhere near, or even facing the detonation
point to damage your targets. You only have to move to a position
where your cone of traces is on them.

- The cone of traces always points the same direction regardless of
which direction you turn.

- You do not have to face your targets in order to hit them.

- You can fire the BFG in a totally different area than where you want
your targets to be damaged.

Players who perform this stunt successfully the first time are usually
amazed that it actually works. This is also a good practice for using
similar moves in real deathmatches.

-- Section 5 - Submitting Corrections --------------------------------------

5A. Common misconceptions

This is a list of the most common misunderstandings about the behavior
of the BFG. Please review this list before submitting corrections.

1) You have to be looking at your target in order to inflict blast
area damage.

This is untrue. The target must be within an imaginary line-of-sight
to you at detonation time, but you can be facing away from the
target, provided it meets all the other criteria.

This is an easy mistake to make because you tend to be more accurate
in positioning your cone of damage if you keep your eyes on your
targets. Especially if you are strafing instead of rotating.

See section 4E for proof of this.

2) You have to see the detonation point in order to inflict blast area
damage.

Nope. The detonation point can be completely out of your range of
sight, and can be separated from you and your targets by a hundred
solid stone walls.

Again, see section 4E for proof of this.

3) The location of the detonation point is a factor in the blast damage
area calculations.

Only the moment of detonation is important. The location of the
detonation point is not used. See number 2, above.

4) The location you were standing when you fired, or the location of
targets at firing time, is a factor.

Only the location where you are standing when the blast detonates
is important. The compass direction that you fired is important,
but not the location where you fired. The traces are only
calculated at detonation time. The game engine does not care where
the targets are until the traces are calculated.

Again, see section 4E for proof of this.

5) You have to be facing the same direction at detonation time as you
were at firing time.

No, the cone of traces extends outward in the same compass direction
regardless of which way you are facing at detonation time.

Again, an easy mistake to make because you tend to be more accurate
if you keep your eyes on your targets. Again, especially if you are
strafing.

Again, see section 4E for proof of this.

6) Your BFG blast can frag someone behind you, but only if they are
close enough to touch you.

You can frag someone behind you if they fall anywhere within the
cone of traces. Sure they can be behind you, but they don't have
to be touching you. In order to frag someone behind you, you must
rotate away from the direction you fired, then maneuver so that
your targets are within the cone behind you.

Having said that, if the victim is standing right next to the
attacker, at 90 degrees perpendicular to the cone of damage, they
will fall within the cone if they are in front of the attacker's
centerline. But if they are truly behind the attacker's cone of
damage (behind the centerline of the attacker), they will walk
away unscathed.

This seems to be due to the fact that the player's 'hittable'
radius is larger than the player's 'walk into' radius. When you
walk up to a player and bump into him, his 'hittable' area is
overlapping into your area.

This is an easy mistake to make when looking at a deathmatch game,
where everyone is moving around each other so quickly that it's
hard to keep track of the location of the cone of damage. If you
really think you fragged someone behind you, it's probably because
of one of two reasons:
1) They were actually next to you and slightly forward of your
centerline.
2) You rotated away from the direction of fire, and the victim
stepped into the cone of damage that still existed behind you.

5B. I think the FAQ is in error. How do I get it corrected?

Please go through this checklist before submitting information:

1) Read the entire FAQ to be sure we did not cover your point in
another section. Check the 'Common Misconceptions' section, above,
too.

2) If you have a theory about the BFG behavior, please test it
carefully before submitting it. If you can't reproduce the effect
under controlled conditions, you were probably witnessing a side
effect of one of its known behaviors. Or perhaps it happened in a
deathmatch game, where the action is so fast that you often can't
keep track of what's going on.

3) If you think you have tested your theory thoroughly and are ready
to submit the theory as proven, please prepare a short, precise
description statement that details how to reproduce the effect
during game play. Demo recordings are not necessary.

4) When you have composed your message, e-mail it to tfabris@oro.net.

5) Note: Do not attempt to send us information for FAQ files other than
this one. We do not maintain other FAQ files and we do not echo
information amongst other FAQ authors.


-- Appendix A - Quake Mods -------------------------------------------------

Quake 1 BFG Mods

The ability to make user-created code modifications to the Quake engine
was one of Quake's most important features. These modifications, called
"patches" or "mods" number perhaps in the thousands. Some of the patch
authors decided that Quake deserved a BFG, too. Here's a short list of
some of the Quake BFG patches I've run across in my travels.

Since Quake's code is totally different than Doom's code, these BFG
remakes can't be precisely like the original BFG. Most of them get
pretty close in terms of "feel", though. The biggest difference is that
they all have a "Z" direction for their damage cone, i.e., they can be
aimed upwards.

Note that this list is not comprehensive and isn't necessarily up to
date.

Deathmatch Plus
URL: http://www.demonic.demon.co.uk/dmplus.html
Author: William Harris
Comments: This patch includes other interesting weapons such as the
Cluster Bomb. This patch was specifically designed for deathmatch play.

The BFG 9500
URL: http://www.trailerpark.com/phase1/nelno/pseudopodia/pseudo.html
Author: Nelno the Amoeba
Comments: Designed for single player.

Doom 2 Total Conversion
URL: http://members.aol.com/imarvintpa/index.htm
Author: Andy Bay
Comments: A Total Conversion project for Quake, allowing you to play
Doom 2 with the Quake engine.

Your Path of Destruction
URL: http://www.planetquake.com/doom
Author: Curtis Moxley
Comments: A Doom Total Conversion project for Quake, including another
original piece of QuakeC code for the BFG.

DeathX
URL: http://omega.simplenet.com/omega/
Author: Luke Whiteside (WeAsL)
Comments: A set of QuakeC modifications for deathmatch play, with
several new weapons including a variation on the BFG.

Requiem
URL: http://www.planetquake.com/requiem
Author: Requiem
Comments: A Conversion for single player and multi player Quake, with
extra attention given to making a balanced set of weapons. Includes
the good-old BFG.

-- Appendix B - Quake 2 ----------------------------------------------------

The Quake 2 BFG10K

Pandora opened the box again! They put a BFG in Quake 2! It's
different from the Doom BFG, and different from the Quake 1 BFG mods.

Randy Pitchford of Rebel Boat Rocker has written up an excellent
Quake 2 Weapons FAQ. This document can be found at:

http://www.rebelboatrocker.com/q2wfaq.htm

Randy and I have corresponded, and between his his team's research and
a few peeks at the Quake 2 public code release, we've got the BFG10K's
behavior pretty much figured out. I'm only going to review it briefly
here, and you can go look at Randy's FAQ for all the details. So, in
other words, the torch has been passed.

Briefly, the main differences between the Quake 2 BFG and the Doom
BFG are:

1) If you detonate it against a wall or floor next to you, there's a
small rocket-style blast radius at the detonation point. It can
hurt you. This is to keep you from using your old Doom BFG tricks.
But it can also allow you to BFG jump, similar to rocket jumping.

2) The green ball shoots green lasers at targets as it flies along.

3) The direct hit is more powerful.

4) The area damage (called the "BFG Effect" in the source code) isn't
done with 40 damage traces. Instead, you must triangulate
lines-of-sight between the target, the detonation point, and the
attacker. In other words, to take damage, the target must be within
an imaginary line-of-sight to both the attacker and the ball.

5) The BFG Effect has a hard-coded 1000-unit range limit, similar to
Doom. But the range is measured from the detonation point instead
of from the attacker. (The way it should be!)

6) The BFG Effect damage amount is up to 500 points per target, with
an inverse square falloff between the detonation point and the
1000-unit limit. Here is the code line:

points = self->radius_dmg * (1.0 - sqrt(dist/self->dmg_radius));

So the farther away the target is from the detonation point, the
less damage the target will take.

In my experiences, the best way to attack with the BFG10K is similar
to the Doom way: Get a target in sight, then quickly detonate the
green ball on a wall, ceiling, or floor next to you. The only twist
is that you need to keep out of the way of the local blast radius.
You also need to make sure that the ball is detonated is a place
that's got a clear line-of-sight to the target. For example,
shooting the back side of a column, unlike Doom, is useless in
Quake 2.

The best way to defend against the BFG10K is to hide and/or run from
the ball. It keeps you out of the way of the lasers, as well as
keeping you out of the way of the BFG effect.

That's about all I need to say about the BFG10K (hey, that rhymes).
Check out Randy's FAQ for the rest. See you on the Quake 2 servers!
I'll be the one gathering cells for my BFG...

================= THE END. Thanks for reading the BFG FAQ! =================