Screeps Articles and Debugging Guides

Spawn and Creep LifecycleIntermediateDebugging

Screeps Arena spawnCreep(): Find Your Spawn

Find your Screeps Arena Spawn with getObjectsByPrototype(), call spawnCreep(body), read object or error results, and avoid mixing Arena with MMO syntax.

8 min read

Spawn Creeps

Operations and DebuggingIntermediateDebugging

Screeps RoomVisual: Transparent Fills, Labels, and Paths

Use fill: 'transparent' for unfilled RoomVisual circles and rectangles, then add debug labels and target paths without confusing visuals with game results.

10 min read

Debugging Rooms JavaScript

Spawn and Creep LifecycleIntermediateDebugging

Screeps Spawn Exit Blocked: Diagnose Directions and Occupied Tiles

Confirm a blocked Screeps Spawn exit from current spawning state and all eight adjacent tiles, then fix direction policy without confusing accepted intents with observed birth.

14 min read

Spawn Creeps

Movement and VisionIntermediateDebugging

Screeps moveTo() Returns OK but the Creep Stays Put

Verify movement over later ticks, then isolate fatigue, repeated movement intents, traffic, cached paths, room edges, and impossible stop ranges.

13 min read

Movement Debugging Pathfinding

Spawn and Creep LifecycleIntermediateDebugging

Screeps spawnCreep() Errors: Diagnose Every Return Code

Capture the actual Spawn request, interpret each documented return code, separate dryRun from the final submission, and verify scheduled spawning across later ticks.

12 min read

Spawn Debugging

Operations and DebuggingIntermediateDebugging

Screeps Room Error Isolation: Keep Other Rooms Running

Catch JavaScript exceptions at room or subsystem boundaries, retain bounded rate-limited evidence, pause repeatedly failing optional work, and retry after cooldown without confusing API return codes or CPU termination with exceptions.

18 min read

Debugging JavaScript

Movement and VisionIntermediateDebugging

Screeps ERR_NO_PATH: Diagnose Range, Matrices, and Routes

Separate ERR_NO_PATH from missing cached paths and incomplete PathFinder searches, then inspect goal range, CostMatrix rules, callbacks, limits, and room routes.

15 min read

Movement Pathfinding Debugging

Movement and VisionIntermediateDebugging

Screeps ERR_NOT_IN_RANGE: Use the Correct Action Range

Find the action that returned ERR_NOT_IN_RANGE, use its documented range, submit movement separately, and retry the action on a later tick.

11 min read

Movement Debugging

Publication standard

English articles are published only after source review, official API checks where applicable, JavaScript syntax review where code is present, duplicate-intent and link checks, and editorial review. Publication does not imply Console or multi-tick live-room verification; those evidence states remain separate in each guide. Review the verification method.