Blobcraft

A multiplayer browser-based RTS where you control blob units that eat enemies and NPCs to grow bigger and stronger. Destroy all enemy bases and units to win.

• Select units: Left-click a blob, or drag to box-select
• Move: Right-click empty ground
• Attack: Right-click an enemy blob or base
• Attack-move: Press A, then click a destination (blobs fight anything along the way)
• Stop: Press S
• Select all: Ctrl+A
• Add to selection: Shift+click
• Pan camera: Arrow keys or move mouse to screen edges
• Minimap: Click the minimap (bottom-right) to jump the camera

• Ctrl+0–9: Assign selected units to a group
• 0–9: Recall a group (select those units)
• Shift+0–9: Add selected units to a group
• Alt+0–9: Steal selected units from other groups and assign to this group
• Shift+Alt+0–9: Steal selected units from other groups and add to this group
• Ctrl+Shift+0–9: Assign to group and remove those units from all other groups

• Your base spawns a baby blob every 3 seconds (max 50 units)
• Green NPC blobs are neutral — eat them to grow
• When two enemy blobs collide, a probability roll determines the winner based on relative size
• The winner absorbs 80% of the loser's mass
• Bigger blobs are stronger but move slower
• Destroy an opponent's base and all their units to eliminate them
• Last team standing wins

npm install
npm start

The server starts on port 3000 by default. Set the PORT environment variable to change it:

PORT=8080 npm start

1. Start the server
2. Open http://localhost:3000 in your browser
3. Share your LAN IP (e.g. http://192.168.x.x:3000) with friends on the same network
4. Up to 8 players can join — each gets a unique color and base position

Each blob's "mass" is its area (π × radius²). When two enemy blobs collide, the win probability is proportional to mass:

P(A wins) = area_A / (area_A + area_B)

For example, a blob with radius 10 (area ~314) fighting one with radius 5 (area ~78) has roughly an 80% chance of winning. Equal-sized blobs have a 50/50 chance. The winner absorbs 80% of the loser's mass.

NPCs are easier to farm — players get a configurable bonus to their effective mass when fighting NPCs. Set npcCombatDisadvantage higher to make NPCs easier (1.0 = equal difficulty).

Blobs near friendly allies gain a combat bonus. Each same-team blob within range adds a stacking multiplier to effective mass during combat. This means a swarm of small blobs can overwhelm a single large blob that lacks support.

Blobs with an active group bonus display a glowing ring and a +N indicator above them showing the stack count.

After a blob eats another blob, it enters a cooldown period during which it cannot fight again. This prevents a single blob from instantly chain-eating an entire group. The cooldown is measured in server ticks (30 ticks per second), so the default combatCooldown of 15 means ~500ms between kills. A separate baseCombatCooldown controls how often blobs can damage enemy bases.

Edit config.json to tune game balance:

{
  "npcCombatDisadvantage": 1.0,
  "groupBonusPerAlly": 0.1,
  "groupBonusRadius": 80,
  "groupBonusMax": 2.0,
  "combatCooldown": 15,
  "baseCombatCooldown": 30,
  "baseDefenseSpawns": 2,
  "npcMaxCount": 80,
  "npcRespawnInterval": 6000,
  "npcRespawnBatch": 3,
  "npcSizeTiers": [
    { "weight": 0.60, "min": 4, "max": 12 },
    { "weight": 0.25, "min": 12, "max": 22 },
    { "weight": 0.12, "min": 22, "max": 35 },
    { "weight": 0.03, "min": 35, "max": 55 }
  ]
}