What are the differences between normal mode and fast mode

[Igor9]

What are the specific changes when you engage fast mode in Doom? Like are the fireballs x0.5 or x2 faster, are the demons x2 faster etc. I'm making dehacked patches again. Also, is there anywhere where I can find info on the Thy Flesh Consumed episode? The FAQ I have doesn't cover these stuff. Thx in advance.

[Grazza]

Demons and spectres move twice as fast.
Monsters attack immediately upon seeing the player (reactiontime = 0); attack chance is much greater.
Fireballs travel faster (I forget by how much - IIRC it depends on the type of fireball).

This has cropped up in the forums before, and some slightly more technical answers given.

[Torn]

with -fast, the monsters move and shot like nightmare without respawn.

[The Ultimate DooMer]

Actually, the demons move 3x as fast.

[Amaster]

Yeah, demons are a nightmare on -fast. And shotgunners are freakin' lethal. Even the lowly zombieman is dangerous.

[Chopkinsca]

yeah, it kind of makes the shotgun dudes and zombie guys the things you have to worry about the most. Which in turn makes large open areas very dangerous.
I like the faster fireballs though. It is so much fun to dodge a barrage of fast moving fireballs, especially in some levels where many imps and such can see you at one time.
:-(=

[Graf Zahl]

The Ultimate DooMer said:

Actually, the demons move 3x as fast.

No, they're moving twice as fast, unless a shift right by one bit has turned into a division by 3... ;-)


Here's the code from PrBoom:

        for (i=S_SARG_RUN1; i<=S_SARG_PAIN2; i++)
          if (states[i].tics != 1 || demo_compatibility) // killough 4/10/98
            states[i].tics >>= 1;  // don't change 1->0 since it causes cycles

[Colusio]

Great, info, it looks actually 3 as fast.
Also really like fighting the imps on fast mode, well not up close. Are they not more dangerous when they use their close attack on fast mode then the demons?

[The Ultimate DooMer]

I always thought it was 3 times as fast. It says in the readme that the monsters move and shoot up to 3 times faster - given that only the demons move faster, it must be them that move 3 times faster.