Units

Every Unit keeps a stable UUID for as long as it lives, takes up one cell slot, moves at most one cardinal cell per Tick, and performs at most one action.

Comparison

Unit	HP	Vision	Cost	Attack	Special role
Worker	2	3	5	-	Harvest and deposit
Vanguard	4	4	10	1 sweep damage	Adjacent area pressure
Ranger	2	5	12	1 shot damage	Range 1-3 precision attack

MOVE, PICKUP_BEACON, DROP_BEACON, and WAIT are available to every Unit. Everything else depends on the type.

Worker

Allowed actions:

• MOVE
• HARVEST
• DEPOSIT
• PICKUP_BEACON
• DROP_BEACON
• WAIT

HARVEST needs an empty-cargo Worker standing on a RESOURCE cell. It picks up 1 resource, or 2 while its owner holds the Champion Beacon. Resource cells never deplete, so if several eligible Workers share one cell they all take a full amount.

Cargo capacity is really just however much the last successful harvest brought in: 1 normally, 2 with the Beacon bonus. Losing the Beacon does not delete bonus cargo a Worker is already carrying.

DEPOSIT needs the Worker to share a cell with its own Core, and that Core has to be normal and receptive — one that is migrating or recovering from a migration cannot take delivery. A failed deposit leaves the cargo alone; only the Worker's death destroys it.

Workers cannot attack at all.

Vanguard

Allowed actions:

• MOVE
• SWEEP with one cardinal direction
• PICKUP_BEACON
• DROP_BEACON
• WAIT

SWEEP hits the adjacent cell in the direction you choose. Every enemy Unit standing there takes 1 damage, and so does an enemy Core. Send several Vanguards at the same cell and their damage adds up inside the shared combat snapshot.

A sweep needs no target UUID, and it will never hurt your own objects.

Ranger

Allowed actions:

• MOVE
• SHOOT with target_id and expected_cell
• PICKUP_BEACON
• DROP_BEACON
• WAIT

A shot is legal only when all of the following hold:

1. the target is an enemy Unit or Core;
2. it is still at expected_cell;
3. target and Ranger sit on one horizontal or vertical line;
4. the Manhattan distance is 1, 2, or 3;
5. no cell in between holds an obstacle, Unit, or Core.

The target cell may hold several colocated objects, and target_id picks one of them. There is no front-to-back ordering to exploit within a cell.

The POST endpoint accepts an unseen or even nonexistent UUID on purpose, so that nobody can use it to probe fog of war. At resolution, a missing target, a friendly target, a target that moved, bad range, and a blocked line all collapse into the same private SHOT_MISSED event.

Action schema examples

Worker harvest

{"type": "HARVEST"}

Vanguard sweep right

{"type": "SWEEP", "direction": "RIGHT"}

Ranger shot

{
  "type": "SHOOT",
  "target_id": "175f47f4-f7de-4785-b45c-9a2d2289a8ea",
  "expected_cell": [120, 85]
}

An action may carry only the fields listed for its own type. One unrelated field rejects the entire plan with UNEXPECTED_ACTION_FIELDS, even if its value is null, an empty string, or the zero UUID.