Spellrot — UE5.7 Prototype

Wizard vs zombie horde arena brawler. The last living wizard holds back endless waves — every hit from a wizard zombie corrupts your spells, making them more powerful but pushing you closer to transformation.

Design & studio: ibrews/spellrot — game concept, design docs, 49-agent Claude Code studio Engine: Unreal Engine 5.7 Base: Third Person Template + ECABridge MCP plugin

Things to Try

1. Open ThirdPersonClass.uproject in UE 5.7 and hit Play (Lvl_ThirdPerson). Enemies (BP_Enemy) spawn from BP_WaveSpawner actors and chase you. Each enemy that reaches you applies 100 damage which raises CorruptionLevel by 0.25. After 4 hits you ragdoll and the level restarts after 3s.
2. Walk into a BP_KOTHZone (yellow cube). On overlap it calls ApplyCleanse on you, resetting CorruptionLevel to 0. Walk out to deactivate.
3. Left-click to fire a line trace. If it hits BP_Enemy, ApplyDamage runs the enemy's ReceiveAnyDamage which casts back to you and subtracts 0.1 from CorruptionLevel, then ragdoll-and-recovers the enemy.
4. Inspect the WBP_HUD widget — it has a CorruptionText field and a CurrentCorruption float variable. The Tick event reads CurrentCorruption and writes the formatted string to CorruptionText. To wire up display in PIE, add a CreateWidget(WBP_HUD) → AddToViewport chain in BP_PlatformingGameMode BeginPlay (currently empty — TODO).
5. Run ECABridge (ECABridge.GenerateClientConfig ClaudeCode in the editor console) then open Claude Code in this directory to drive the editor via MCP.

Setup

1. Unreal Engine 5.7 required (Epic Games Launcher)
2. Open ThirdPersonClass.uproject — accept any "missing modules" prompt
3. For ECABridge (AI-assisted development):

   # In UE editor console:
   ECABridge.GenerateClientConfig ClaudeCode
   

   Then in terminal:

   claude mcp list   # should show unreal-ecabridge

Mechanics Implemented (2026-05-21)

Mechanic	File	Notes
Corruption accumulation	BP_PlatformingCharacter	ReceiveAnyDamage → CorruptionLevel += 0.25; branch on >= 1.0 → ragdoll + delay 3s + OpenLevel("/Game/ThirdPerson/Lvl_ThirdPerson")
Cleanse zone reset	BP_KOTHZone	BeginOverlap casts to BP_PlatformingCharacter, sets IsActive=true, calls ApplyCleanse on player. EndOverlap clears IsActive.
Fireball	BP_PlatformingCharacter	IA_Fire (Started) → LineTraceByChannel → branch on hit → cast to BP_Enemy → ApplyDamage(100)
Enemy damage relay	BP_Enemy	ReceiveAnyDamage → cast to player → CorruptionLevel -= 0.1 → RagdollAndRecover (2s ragdoll then restore)
Trail color shift	BP_PlatformingCharacter	BeginPlay activates Trail_L/Trail_R Niagara; Tick lerps User.Color parameter from base to magenta as corruption rises
Wave spawning	BP_WaveSpawner	Timer calls SpawnWave every SpawnInterval seconds, spawns BP_Enemy at spawner transform. 3 spawner instances in level.
HUD widget	WBP_HUD	Static ScoreText + dynamic CorruptionText bound to CurrentCorruption member float via Tick. Wiring to gameplay still TODO.

Known TODOs

• HUD spawn: Add CreateWidget(WBP_HUD) → AddToViewport to BP_PlatformingGameMode BeginPlay. CreateWidget is a K2 macro and cannot be added through ECABridge's add_blueprint_function_node — needs manual editor work.
• HUD ↔ player wiring: When CorruptionLevel changes on player, push value to HUDWidget.CurrentCorruption. Requires HUDWidget reference variable on player + setter calls.
• Wave scaling: Increment WaveCount each SpawnWave and use it to spawn additional enemies. lisp_to_blueprint keeps dropping the actor class on BeginDeferredActorSpawnFromClass when nested in branches — needs manual surgery.
• Enemy color tint: Visual distinction for fast/tanky variants.
• Score display on death: Kills + time survived on game-over screen.

ECABridge Patterns

See the design repo for the full pattern catalog: docs/engine-reference/unreal/ecabridge-patterns.md

Patterns learned this session

• lisp_to_blueprint cross-BP variable set: (set CorruptionLevel ...) inside a (cast) body does NOT properly target the cast result — it tries to resolve on the casting BP. Workaround: define a custom event on the target BP that does the set, then call it from the casting BP using add_blueprint_function_node with target_class pointing to the target's _C class.
• (call FunctionName) inside (cast): Breaks the cast's Object pin (becomes wildcard) and the compile fails. Use surgical add_blueprint_function_node + connect_blueprint_nodes instead.
• (print float) in lisp: Auto-resolves to PrintString expecting a string, fails with float-to-string compile error. Workaround: drop the print or pre-convert.
• CreateWidget not addable via function_node: It's a K2Node_CreateWidget macro, not a regular function. ECABridge has no surface for it yet — must add in editor manually.
• Always reload from git after a broken lisp_to_blueprint rebuild: delete_loaded_asset unloads the asset and orphans the in-memory state. git checkout + scan_paths_synchronous(force_rescan=True) restores cleanly.