Cowboys vs Zombies

A handful of cowboys hold a saloon against a horde of the dead coming in through the swinging doors - two of them for every one of the living. Played entirely by AI on both sides, built on Brawl Bots. If the dead win, they eat the cowboys; if the cowboys win, they set every last zombie alight. Part of the Precog sim suite.

Live: https://cowboys-vs-zombies.apps.precogsoftwareservices.com

The dead

• Only the head stops one for good. Body hits stagger it, knock it flat (a shotgun close in, a boot) and in the end wear the body out (about 15% of kills); a shot leg puts it on its belly, crawling. Its head lolls and lurches, so a man who laid his sight on it may still miss.
• Limbs come off. A slug in an arm or leg can take it clean off (likelier on a limb already hit, less on a brute); it lands on the boards. One leg: a lurching hop at half speed. No legs: it crawls, and from the floor it can only get an ankle. One arm: a weaker grip that slips. No arms: nothing to grab with - it can only lunge in with its teeth, and can't hold a man there. About 3-4 limbs come off a match.
• Kinds: Shambler (slow, the bulk of any horde), Runner (fresh dead: sprints like a living man, goes down easier), Brute (huge, slow, soaks body shots, bites hard), or Mixed (mostly shamblers, a couple of runners and a brute). Grades - Rotten, Walker, Hungry, Alpha - are how fresh and sharp they are, never how tough.
• The grip: in reach a zombie lunges; a lunge that lands is a grip, and a man held can't aim. It bites until he's dead (the throat ends it at once) - unless he punches or kicks it loose, his friends shoot it off him, or he gets his Colt up under its jaw (the point-blank shot). Others smell the blood and pile on the man already held.
• How the horde comes on: Swarm (straight at the nearest), Surround (spread out so every man has some coming from his side), Wave (mass inside the doors, then all come at once, in a frenzy).
• Its personality reads four traits its own way: aggression (lunges sooner, piles on), cunning (comes round the side), teamwork (keeps with the horde), and hunger (stops to feed on a fallen man - and gives the living a breath).

The living

Everything from Brawl Bots: the seven temperaments, the team plans, grades, weapons per side or per man (Colt, shotgun, rifle, lasso, knives, bottles), and the AI as editable rules. Against the dead they give ground and shoot - back off as one closes, lay the sight on the head when they have the time and the nerve, centre of mass when they haven't - and the 3 m no-shooting rule does not apply: you can put a slug in a zombie's face.

At 2:00 the living who are still standing hold out till dawn and win.

Balance (headless; 160 matches at the defaults: 10 Mixed vs 5 Balanced cowboys on Dig In)

Zombies 37, Cowboys 43 over 80 after limbs came off (46% for the dead). About 85% of the dead put down go by the head; ~12 grips, ~12 bites and ~1 point-blank shot a match. Temperament matters: Balanced and Lawman hold the line best (about half), Brawlers about 40%, Sharpshooters and Desperados about a third, and Gunslingers (fanning the hammer: wild body shots) and Cowards (cowering) rarely survive. Wave is the strongest horde plan, Swarm and Surround about level.

The view

Every match starts wide, the whole saloon in shot. Bottom right: pan (arrows, with Wide in the middle to put the whole map back), rotate, tilt and zoom - hold to keep going; Hide view controls tucks them away. Mouse: drag to orbit, right-drag (or shift-drag) to pan, wheel to zoom. Touch: one finger orbits, two pinch and pan. Keys: arrows/WASD pan, Q E rotate, R F tilt,

• • zoom, Home or 0 for wide.

Rules of the fight

• Last side standing wins. Three-second standoff. At 2:00 the side with more men standing wins on decision; level, it's sudden death - next man down loses it.
• Vital hits kill, always: head or heart - slug, blade or star. Gut shots hurt badly and bleed. Arm and leg hits cost little blood but cripple: the gun hand goes to the off hand, reloads and blows slow, both arms and he can't punch; one leg is a limp, both and he crawls. Every wound bleeds - one is about a minute from death, two about half that. Blood pools on the floor and men can slip in it.
• Aim time is accuracy: spread x(1 + 2.2 e^(-t/0.42)). Six in the Colt, 18 rounds in all, then fists. Guns jam, especially in a scuffle; a punch to a raised gun can jam it.
• Inside 3 m nobody shoots. A gunman running in pulls up short of it to fire; a man caught inside it closes in to fight, backs off to make room, or throws whatever he has - a bottle or a chair. In arm's reach men punch, kick (a boot drives a man back a stride and can drop him - or send him over the rail) or grab hold and wrestle: both locked a second or two, guns liable to jam, until one throws the other down. Blade- and staff-men still swing, short, and kick.
• Blades and staffs: reach, wind-up, and the other man's defence - he can block a blow he sees coming (and a star), parry and riposte, or dodge. A katana cuts (bleeds; finds the throat and heart more often in a better swordsman's hands); nunchaku and staff bruise, break limbs and ring skulls (knockdowns). Bottles come off the bar, the shelf and every table: an empty or jammed gunman (or a brawler) throws one at a head (a skull hit knocks him flat) or breaks it over one. Over the rail: a man shot or hit at the balcony's edge goes through the balustrade and the fall kills him; off a low roof it only knocks him flat. Throwing stars are silent, slower than a slug, rarely kill outright and always bleed.

The AI

Team brain (scripts/team_brain.gd): a blackboard of every enemy seen or heard, counting every shot (rush a man counted empty); a tactical map scoring every spot for cover, sight lines and the angles that beat the enemy's cover; and a commander running one of seven plans - Adaptive, Dig In, Rush, Pincer, High Ground, Leapfrog, Bait - with clock sense in the last 25 s.

Each man (scripts/gunman.gd): ten personality traits weight a utility score over the map, blended with his orders by his discipline. He is always in a mode you can see over his head: hold, advance, duck, hide, cower, flank, rush, fall back, brawl, hunt - and he walks the map his legs allow: vaulting low cover and water, dropping off decks, leaping up onto them, climbing ladders.

The rules (scripts/ai_script.gd) - the exposed AI. Each side can run a script, edited in the app (Teams / tactics -> Edit AI rules), checked with line-numbered errors (with "did you mean" for typos), saved in the browser. Type a few letters and it suggests what can go there - a condition, a number, an action, a trait - with what it means (Tab or tap to take one); the word under the cursor is explained; Add an example drops in a ready-made rule:

# first rule that holds (and can be done) wins; anything uncovered -> built-in brain
set caution 0.85
aim 1.25
when pinned -> hide for 2
when bleeding and bleed_secs < 15 -> rush nearest for 3
when enemy_reloading and nearest < 8 -> rush reloading
when super and stalemate -> flank
when melee and in_reach -> rush nearest
otherwise -> default

About 35 yes/no conditions (bleeding, pinned, aimed_at, enemy_reloading, high, edge, clinch, outnumbered, super, melee, in_reach, has_bottle, near_bottle, ...), 14 numbers (hp, bleed_secs, ammo, nearest, time, diff, random, ...), 12 actions (hold, advance, hide, flank, rush nearest|weakest|reloading|high|aiming|melee, fall back, take high, hunt, flip table, grab bottle, cower, default), set <trait> and aim <multiplier>. Presets to start from: Careful hands, Wild bunch, High ground first, Ninja ambush, Supers lead minions swarm, Last stand. Show intents prints which rule each man is following; the results list how often each rule decided.

Running it

Query string = command line: ?living=6&ratio=2.5&horde=Wave&blue=Sharpshooter&speed=2, ?endtest=0 / ?endtest=1 (debug: the other side drops dead four seconds in, to see the ending), ?map=bamboo&redf=lotus&bluef=law&redn=2&redgrade=Super&bluen=5&bluegrade=Minion&intents=1, ?redscript=Ninja ambush, ?lineup=1, ?cam=10. Headless (Godot 4.4+):

godot --headless --path . -- --sim=20 --horde=Surround --living=5 --ratio=2 --blue=Lawman
godot --headless --path . -- --sim=20 --map=temple --redf=dragon --bluef=outlaws --redgrade=Super --redn=3 --bluen=8
godot --headless --path . -- --sim=20 --redscript=my.rules       # a rules file
godot --headless --path . -- --league=5 [--pairs=Rush:Dig In] [--part=0/4]
godot --headless --path . -- --presets=5

Build and deploy

bash build.sh (Godot 4.7.2 + web templates) exports to dist/, boot-checks the pack and gzips. Dockerfile + nginx.conf serve it; headers.caddy adds COOP/COEP. Meshes and most sounds are built in code; the voices are espeak-ng lines baked into sfx/voice/ by tools/make_voices.sh.