lava or spikes that hurt the player on contact

Hazards are a trigger-plus-script PATTERN. A trigger collider over the danger area fires a handler that applies damage or kills and respawns the player. Water is a real WaterComponent for the look; ctx.water.isSubmerged and surfaceLevelAt let a script react to swimming or drowning. There is no DamageOnContactComponent.

kill floor that respawns the player who falls out of bounds

Hazards are a trigger-plus-script PATTERN. A trigger collider over the danger area fires a handler that applies damage or kills and respawns the player. Water is a real WaterComponent for the look; ctx.water.isSubmerged and surfaceLevelAt let a script react to swimming or drowning. There is no DamageOnContactComponent.

swimmable water the player can go into

Hazards are a trigger-plus-script PATTERN. A trigger collider over the danger area fires a handler that applies damage or kills and respawns the player. Water is a real WaterComponent for the look; ctx.water.isSubmerged and surfaceLevelAt let a script react to swimming or drowning. There is no DamageOnContactComponent.

damage zone that drains health over time

Hazards are a trigger-plus-script PATTERN. A trigger collider over the danger area fires a handler that applies damage or kills and respawns the player. Water is a real WaterComponent for the look; ctx.water.isSubmerged and surfaceLevelAt let a script react to swimming or drowning. There is no DamageOnContactComponent.

Hazards lava damage zones and water

The recipe

Author with project_apply_script_semantic_patch using the ai_safe op pack.

Instant kill floor / pit: a large flat entity with a trigger ColliderComponent (collision:"trigger") under the level. On enter, addTriggerHandler { "handlerKey":"onFallOut" } and respawn the player at the last checkpoint (see spawn-points-and-checkpoints and combat-damage-and-respawn).
Damage zone (lava, gas): a trigger over the danger area. Apply damage on enter for a hit, or for damage-over-time keep a set of entities currently inside (mark on enter, clear on exit) and addTickHandler that incrementNumericState their health field down by a per-second amount scaled by ctx.delta; on zero, run the death flow.
Water look: attach a WaterComponent (set surfaceLevel, color, waveProfile) for the planar surface. It is a presentation component, not a physics volume; it does not by itself slow or drown anyone.
Swim / drown logic: in a whole-body GessaScript body (replaceScriptFromGessaScript), call ctx.water.isSubmerged for the player's point or ctx.water.surfaceLevelAt to compare against their height, and react (buoyancy, an oxygen countdown, or damage below the surface).
Telegraph the danger with particles-and-visual-effects (bubbles, embers) and a hazard-colored DecalComponent or HighlightComponent.

Pitfalls

WaterComponent renders water; it does NOT create a swim volume or apply drag. Any swim or drown effect is script logic keyed off ctx.water.*.
Hazard colliders must be trigger; a solid lava slab blocks the player instead of hurting them.
Damage-over-time must scale by ctx.delta; a flat per-tick subtraction kills faster on higher tick rates.
Store health in durable state and run death server-side; a client-only kill desyncs across players.
The collision system caps at 1000 entities per tick; one big hazard trigger is far cheaper than hundreds of small overlapping ones.

Verify

simulation_run (qa.run.start) to prove contact damages or kills, a fall respawns the player, and submersion in water triggers the swim reaction.
project_get_graph_snapshot to confirm the hazard triggers, handlers, and any WaterComponent are present.

The recipe

Pitfalls

Verify

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