Battle Game

A wobbly 3D ragdoll battle sandbox in the browser. Place two armies, press Fight!, and watch physics sort it out.

Play: https://kyleleesea.github.io/battle-sim/

Units

67 of them. The serious ones: Peasant, Squire, Hoplite, Berserker, Knight, Ninja, Archer, Musketeer, Stone Thrower, Bomber, Wizard, Storm Caller, Healer, Sumo and Giant. The less serious ones:

Unit	Trick
Chicken	Pecks ankles. Ten gold each, so bring a hundred.
Squirrel	Pounces in swarms.
Grandma	Rolling pin.
Fishmonger	A fish slap that sends people flying.
Scarecrow	Enemies can't resist attacking it.
Monkey	Throws banana peels; whoever steps on one slips over.
Jester	Cream pies that leave targets staggering, blinded.
Pirate	A hand cannon firing real cannonballs.
Cupid	Love arrows make enemies switch sides for six seconds.
Bard	Music that makes nearby allies fight and run faster.
Disco Dancer	Every enemy nearby has to stop and dance.
Witch	Turns enemies into chickens. Giants included.
Robot	A laser that never misses.
Treant	A grumpy old oak that swats whole rows aside.
LeBron James	Bouncing basketballs from range, slam dunks up close.
Fish	Summons little fish, three at a time.
Databrick	A literal brick. Hops onto people; very hard to break.
Hog Rider	Rides a hog. Very fast, has a hammer.
Miner	Tunnels underground and pops up behind enemy lines.
DJ Khaled	Another one: pumps up allies and clones one every other song.
Mega Knight	Leaps onto crowds and lands like a meteor.
Dragon	A Chinese dragon in a rice hat. Breathes fire in a wide cone.
Ultraman	A giant of light, twice a Giant's height. Stomps enemies underfoot; fires the Specium Ray.
Kendrick Lamar	Sound waves that pierce a whole line. Hits Drake twice as hard.
Drake	Makes it rain: enemies hit by cash stop to pick it up.
Anderson .Paak	Drums so hard the shockwaves knock everyone nearby over.
Nicki Minaj	Super Bass: a blast that sends everyone in front of her flying.
St. Augustine	Heals every ally around him at once.
Martin Luther	Here I stand: can't be knocked off his feet. Fights with a hammer.
Dietrich Bonhoeffer	Allies standing near him take a third less damage.
Martin Luther King Jr.	Never strikes a blow. Inspires allies and makes nearby enemies lay down their arms.
Pastor Hans	Prays over fallen allies and brings back up to five.
Tung Tung Tung Sahur	A wooden log with a bat. Hits home runs with people.
Elon Musk	Launches rockets. About one in ten blows up on the launch pad.
Mark Zuckerberg	Definitely not a lizard. Reels enemies in with a very long tongue.
Jensen Huang	The more you buy, the more you save: nearby allies hit 50% harder.
Corporate Spy	Disguised as the enemy until it strikes; goes for the most expensive target.
Sam Altman	Fired, then rehired: comes back four seconds after he first goes down.
Software Engineer	Writes bots that fight for him, up to three.
On-call Engineer	Fights fast, but stops every few seconds to answer the pager.
Giant Armadillo	Curls into an armoured ball and bowls through crowds.
Big Bird	Eight feet of friendly yellow bird. Flaps everyone out of the way.
Nathan Fielder	Hires actors to play himself. Enemies go after the actors.
Elizabeth Holmes	Blood tests with the Edison. The results look amazing. (They heal 1 HP.)
Duck	4,000 gold. Its QUACK flattens everything nearby, it can't be knocked over, and it flaps onto anyone who runs.
Squirrel King	Summons squirrels five at a time; his royal decrees make them fight twice as hard.
Minion	Small, yellow, enthusiastic. Best by the dozen.
Gru	A freeze ray that turns enemies into blocks of ice. Brings six Minions.
Joseph Joestar	Clacker volleys and a lot of dodging. When hurt, he runs away and breathes his health back.
Jotaro Kujo	Star Platinum: a barrage of punches. ORA ORA ORA!
DIO	ZA WARUDO stops time for every enemy; then MUDA MUDA, then a road roller from the sky.
Naruto	Shadow Clone Jutsu brings four clones that vanish when hit; the Rasengan can't be blocked.

Units lighter than a person (Chickens, Little Fish, Squirrels, Monkeys, Cupids, Grandmas) get a speed boost that grows as their mass drops, so the smallest ones scurry at more than twice a person's pace.

Maps

Map	Twist
Meadow	None. Rolling green hills.
Basketball Court	Polished hardwood in an arena: feet slip and bodies slide.
Tech Office	Thick carpet: nobody slides very far.
Epic Arena	A walled colosseum: nobody gets thrown out of the fight.
Outer Space	A floating platform with very low gravity. Get knocked off it and you drift away for good.
Desert	Soft sand: everyone trudges slower and stops sliding sooner.
Frozen Lake	Ice: feet skid and knocked-over units slide a long way.
The Moon	Low gravity: hits send units much higher and further.
Volcano	A rock island in a lava lake, with lava pools down the middle. Lava burns.
Candy Land	Jelly ground: everything that falls bounces.

Online, the host picks the map.

Controls

• Click your half of the field to place the selected unit; drag to paint a crowd; right-click to remove.
• Right-drag turns the camera, scroll zooms, Shift-drag pans. During a battle, left-drag also turns the camera.
• Game speed: 0.3×, 1×, 2×, 4× or 8× from the top bar, or step it with [ and ]. Speed is local, so online opponents can watch at different speeds.
• Keys: Space to fight, 1–9 to pick units, E for the eraser, R to reset the view, C for the cinematic camera.

Online duels

Press Play online, then Host a match and send your friend the invite link (or the 4-letter code). The two browsers connect directly over WebRTC; PeerJS's free public server only introduces them.

While you deploy, your opponent sees your units only as black "?" stand-ins: just their positions are sent. The full army is sent when you press Ready, and both armies are revealed when the battle starts.

Only armies and a "ready" number travel between players. The simulation is deterministic (seeded random numbers and hand-written trig, so every browser computes the same floating-point results), so both screens play out the exact same battle. If you change the simulation, bump PROTO in net.js (and the ?v= on the script tags in index.html) so players on old and new builds refuse to match and browsers fetch fresh files.

Running locally

No build step. Serve the folder with any static server, for example:

python3 -m http.server 8000

then open http://localhost:8000.

Files

• physics.js: Verlet ragdolls, seeded random numbers, deterministic trig
• units.js: unit roster, AI, poses and melee
• projectiles.js: arrows, bullets, boulders, fireballs, explosions, particles
• painter3d.js, scene3d.js: three.js rendering, camera and scenery
• game.js: deployment, battle loop and controls
• net.js: peer-to-peer matches