(thing) by phraggle Sun Jan 13 2013 at 1:46:26

Classic Doom was full of memorable elements: the shotgun and chainsaw, floating red Cacodemons and roaring Cyberdemons. Deathmatch and space marines, zombies and FM synthesized heavy metal music.

One thing memorable to anyone who's played Doom is the face in the status bar. Oddly, Doom fans never seem to have come up with a catchy name for him other than "status bar face". He sits at the bottom of the screen, responding to all your in-game misfortunes in a surprisingly expressive manner: scanning the room back and forth for demons, his head gradually drooping down as your health drops, and then looking up with a blood-drenched twisted smile as you find that shotgun you really need.

To remember Doom's status bar face is to remember an earlier, more innocent time in the first person shooter genre. Modern FPSes focus on serious realism above all else; Doom is from a time when the genre still hadn't entirely shaken off Wolfenstein 3D's turkey meal style. Other remnants include the blue soul sphere powerups, which were originally intended to be extra lives.

But the status bar face conceals a secret, one that many people don't know about, even those who spent hundreds of hours in dark rooms blasting demons during their youth. But perhaps by chance some of them stumbled across it by accident on occasion, blinked and then wondered if they were hallucinating. The ouch face.

There are seven different "poses" that the player normally sees the status bar face in. In all of these he's usually fairly stoic and restrained. But the eighth - the ouch face - is quite different. Our humble marine is wide-eyed, his jaw dropped and mouth wide open, like he's just seen something truly terrifying, or perhaps he's just screaming for his mother. Given Doom's storyline we can hardly blame him. It's called "ouch face" because the internal graphic lumps that store it are named "STFOUCH".

The slightly comical look to the ouch face, and the fact that it almost never appears, might lead some to speculate that it's an easter egg. But in fact, it isn't - at least not an intentional one. The ouch face is a bug - a logic bug in Doom's status bar code. Thanks to Id's practise of releasing the source code to their games, it's possible to discover the truth behind the ouch face mystery. 

if (plyr->damagecount
    && plyr->attacker
    && plyr->attacker != plyr->mo)
{
    // being attacked
    priority = 7;

    if (plyr->health - st_oldhealth > ST_MUCHPAIN)
    {
        st_facecount = ST_TURNCOUNT;
        st_faceindex = ST_calcPainOffset() + ST_OUCHOFFSET;
    }

This is the code that sets the ouch face. In plain English, it reads "if the player took damage, and their health has dropped by more than a large threshold, set the ouch face". At least, that's what it's supposed to do. It actually does it when the health has increased by more than a large threshold. Someone got the comparison (>) the wrong way round.

With that in mind it's not difficult to see why it's hardly ever seen. Taking damage is usually associated with losing health. To trigger it, one must take some damage and simultaneously gain a large amount of health, enough to exceed the threshold (which, by the way, is 20 health units).

There are parts of the Doom source code that show that the game was put together in quite a rush. The whole game was put together in just over a year, which seems amazing considering the long development cycles of modern games. In a year, a small team of talented people put together one of the most well-known, influential games of all time. There are a few other similar bugs to this one hidden in the Doom source code, but the ouch face is by far the most interesting of them.

Interestingly, when Id made Doom 3, they included the ouch face in the game as a nod to the original game. In several areas of the game there are discarded copies of "GameHOG" magazine, which shows it on the cover. Perhaps Id thought the poor ouch face hadn't got the air time he deserved. Or perhaps they just found him as comical looking as the rest of us.

A step-by-step guide to reproducing the ouch face

  1. Download yourself a copy of DOSbox from www.dosbox.com, and a copy of Shareware Doom (filename doom19s.zip). Install one in the other; the details of this are left as a nostalgic exercise for the reader.
  2. Fire up Doom, start a new game on the lowest skill setting (we don't want the monsters interfering in our experiment)
  3. Warp to E1M4: type IDCLEV14
  4. Go through the door and turn left. Take the corridor at the furthest end of the room. You will find a room with a long line of barrels. Drop down into the river of green slime and follow it along to the left.
  5. You are now in a room with a rocket launcher and an elevator. Get the rocket launcher and go to the elevator. Stand on the very edge of the elevator and press the button on the wall to activate it.
  6. You're now standing with a rocket launcher and a blue soul sphere in front of you. Fire a rocket at the wall in front of you and walk forward to pick up the soul sphere just slightly after it hits the wall. If you time it right, you will take splash damage from the rocket explosion and pick up the soul sphere at roughly the right time.

I like it! 1 C!