roly_poly_spawner_device: Rideable Critters That React to Your World

Overview

The Roly Poly Spawner Device (roly_poly_spawner_device) manages a single Roly Poly creature on your island. Drop one in UEFN, wire it to a Verse device, and you can:

• Spawn / Dismiss the creature at any time with Spawn() and Dismiss().
• Force a rider onto the creature with Ride(Agent).
• Query the live creature reference with GetActiveRolyPoly() (failable — it returns ?roly_poly).
• React to every lifecycle moment via six events: SpawnEvent, FleeEvent, RideEvent, DismountEvent, FrightenEvent, and SootheEvent.

When to reach for it

The device inherits from creative_device_base and enableable, so you can also Enable() / Disable() it through the standard interface.

API Reference

roly_poly_spawner_device

Device for spawning a Roly Poly

Full public surface, resolved verbatim from the live Epic digest (Fortnite.digest.verse).

roly_poly_spawner_device<public> := class<concrete><final>(creative_device_base, enableable):

Events (subscribe a handler to react):

Methods (call these to make the device act):

Walkthrough

Scenario: The Roly Poly Rodeo

A pressure plate sits in the arena. When a player steps on it:

1. The Roly Poly spawns.
2. That player is automatically placed in the saddle.
3. If the creature gets frightened, a cinematic plays and a timer starts.
4. When soothed, the timer stops and the player earns a score bonus.
5. On dismount, the creature is dismissed and the plate is re-armed.

Place in your level:

• One roly_poly_spawner_device → RolyPolySpawner
• One trigger_device (pressure plate) → ArenaTrigger
• One cinematic_sequence_device → FrightenCinematic
• One timer_device → SootheTimer
• One score_manager_device → ScoreManager

roly_poly_rodeo_device := class(creative_device):

    # ── Editable references ──────────────────────────────────────────
    @editable
    RolyPolySpawner : roly_poly_spawner_device = roly_poly_spawner_device{}

    @editable
    ArenaTrigger : trigger_device = trigger_device{}

    @editable
    FrightenCinematic : cinematic_sequence_device = cinematic_sequence_device{}

    @editable
    SootheTimer : timer_device = timer_device{}

    @editable
    ScoreManager : score_manager_device = score_manager_device{}

    # Track who stepped on the plate so we can put them in the saddle
    var CurrentRider : ?agent = false

    # ── Lifecycle ────────────────────────────────────────────────────
    OnBegin<override>()<suspends> : void =
        # Subscribe to the pressure plate — handler receives the triggering agent
        ArenaTrigger.TriggeredEvent.Subscribe(OnPlateTriggered)

        # Roly Poly lifecycle events
        RolyPolySpawner.SpawnEvent.Subscribe(OnRolyPolySpawned)
        RolyPolySpawner.RideEvent.Subscribe(OnRide)
        RolyPolySpawner.DismountEvent.Subscribe(OnDismount)
        RolyPolySpawner.FrightenEvent.Subscribe(OnFrighten)
        RolyPolySpawner.SootheEvent.Subscribe(OnSoothe)
        RolyPolySpawner.FleeEvent.Subscribe(OnFlee)

    # ── Plate handler ────────────────────────────────────────────────
    # trigger_device sends ?agent — unwrap before use
    OnPlateTriggered(MaybeAgent : ?agent) : void =
        if (Agent := MaybeAgent?):
            set CurrentRider = MaybeAgent
            # Spawn the Roly Poly (dismisses any existing one first)
            RolyPolySpawner.Spawn()
            # Disable the plate until this round ends
            ArenaTrigger.Disable()

    # ── SpawnEvent handler (listenable(tuple()) — no payload) ────────
    OnRolyPolySpawned(Unused : tuple()) : void =
        # Now that the creature is alive, force our rider into the saddle
        if (Rider := CurrentRider?):
            RolyPolySpawner.Ride(Rider)

    # ── RideEvent handler (listenable(agent)) ────────────────────────
    OnRide(Rider : agent) : void =
        # Start the soothe timer as a riding challenge clock
        SootheTimer.Start(Rider)

    # ── DismountEvent handler (listenable(agent)) ────────────────────
    OnDismount(Rider : agent) : void =
        SootheTimer.Reset(Rider)
        # Dismiss the creature and re-arm the plate for the next player
        RolyPolySpawner.Dismiss()
        ArenaTrigger.Enable()
        set CurrentRider = false

    # ── FrightenEvent handler (listenable(?agent)) ───────────────────
    OnFrighten(MaybeAgent : ?agent) : void =
        # Play the cinematic regardless of who caused the fright
        FrightenCinematic.Play()
        # If we know the frightener, reset their timer as a penalty
        if (Agent := MaybeAgent?):
            SootheTimer.Reset(Agent)

    # ── SootheEvent handler (listenable(?agent)) ─────────────────────
    OnSoothe(MaybeAgent : ?agent) : void =
        FrightenCinematic.Stop()
        if (Agent := MaybeAgent?):
            # Award bonus points to whoever soothed the Roly Poly
            ScoreManager.Activate(Agent)

    # ── FleeEvent handler (listenable(tuple()) — no payload) ─────────
    OnFlee(Unused : tuple()) : void =
        # Creature fled — clean up state and re-arm the plate
        ArenaTrigger.Enable()
        set CurrentRider = false

Line-by-line highlights

Common patterns

Pattern 1 — Query the live Roly Poly and adjust its health

Use GetActiveRolyPoly() (failable, <transacts><decides>) to read or modify the creature mid-game.

roly_poly_health_check_device := class(creative_device):

    @editable
    RolyPolySpawner : roly_poly_spawner_device = roly_poly_spawner_device{}

    @editable
    HealTrigger : trigger_device = trigger_device{}

    OnBegin<override>()<suspends> : void =
        RolyPolySpawner.Spawn()
        HealTrigger.TriggeredEvent.Subscribe(OnHealTriggered)

    OnHealTriggered(MaybeAgent : ?agent) : void =
        # GetActiveRolyPoly is failable — use if to unwrap
        if (RolyPoly := RolyPolySpawner.GetActiveRolyPoly[]?):
            # Restore the Roly Poly to full health (SetHealth is on roly_poly)
            RolyPoly.SetHealth(RolyPoly.GetMaxHealth())

Note: GetActiveRolyPoly has the <transacts><decides> effect specifier, so it must be called inside a failable context (an if expression). It returns ?roly_poly, so unwrap the option with ? after the call.

Pattern 2 — Spawn on demand and auto-ride the first player who mounts

Demonstrates Spawn() + RideEvent without a pressure plate.

roly_poly_auto_mount_device := class(creative_device):

    @editable
    RolyPolySpawner : roly_poly_spawner_device = roly_poly_spawner_device{}

    @editable
    ScoreManager : score_manager_device = score_manager_device{}

    OnBegin<override>()<suspends> : void =
        RolyPolySpawner.RideEvent.Subscribe(OnFirstMount)
        RolyPolySpawner.DismountEvent.Subscribe(OnPlayerDismounted)
        # Spawn immediately when the game starts
        RolyPolySpawner.Spawn()

    # RideEvent sends a plain `agent` (not optional)
    OnFirstMount(Rider : agent) : void =
        # Give the rider a point for successfully mounting
        ScoreManager.Activate(Rider)

    OnPlayerDismounted(Rider : agent) : void =
        # Respawn a fresh Roly Poly for the next contestant
        RolyPolySpawner.Spawn()

Pattern 3 — Frighten / Soothe puzzle gate

A door stays locked until the Roly Poly is soothed. Uses FrightenEvent and SootheEvent to drive a cinematic lock/unlock.

roly_poly_puzzle_gate_device := class(creative_device):

    @editable
    RolyPolySpawner : roly_poly_spawner_device = roly_poly_spawner_device{}

    @editable
    DoorOpenCinematic : cinematic_sequence_device = cinematic_sequence_device{}

    @editable
    DoorCloseCinematic : cinematic_sequence_device = cinematic_sequence_device{}

    var DoorOpen : logic = false

    OnBegin<override>()<suspends> : void =
        RolyPolySpawner.SpawnEvent.Subscribe(OnSpawned)
        RolyPolySpawner.FrightenEvent.Subscribe(OnFrightened)
        RolyPolySpawner.SootheEvent.Subscribe(OnSoothed)
        RolyPolySpawner.Spawn()

    OnSpawned(Unused : tuple()) : void =
        # Ensure door starts closed whenever a new Roly Poly appears
        if (DoorOpen?):
            DoorCloseCinematic.Play()
            set DoorOpen = false

    # FrightenEvent payload is ?agent — unwrap if you need the instigator
    OnFrightened(MaybeAgent : ?agent) : void =
        if (DoorOpen?):
            DoorCloseCinematic.Play()
            set DoorOpen = false

    # SootheEvent payload is ?agent — the soother gets credit
    OnSoothed(MaybeAgent : ?agent) : void =
        if (not DoorOpen?):
            DoorOpenCinematic.Play()
            set DoorOpen = true

Gotchas

1. SpawnEvent and FleeEvent send tuple(), not agent

These two events carry no agent payload. Their handler signature must be:

OnSpawned(Unused : tuple()) : void = ...

Writing OnSpawned(Agent : agent) will cause a type mismatch at compile time.

2. FrightenEvent and SootheEvent send ?agent — always unwrap

The instigating agent is optional (the creature can be frightened by environmental triggers with no player involved). Always guard with if (Agent := MaybeAgent?): before calling any agent-typed API.

3. GetActiveRolyPoly is failable — call it inside if

GetActiveRolyPoly is marked <transacts><decides> and returns ?roly_poly. You must call it in a failable context:

# CORRECT
if (RP := RolyPolySpawner.GetActiveRolyPoly[]?):
    RP.SetHealth(100.0)

# WRONG — compiler error: expression is not failable here
let RP := RolyPolySpawner.GetActiveRolyPoly[]

4. Ride() does nothing if no Roly Poly is alive

Call Ride(Agent) only after SpawnEvent fires. Calling it immediately after Spawn() (synchronously) may race the spawn — subscribe to SpawnEvent and call Ride from the handler, as shown in the Walkthrough.

5. Spawn() dismisses an existing creature first

If a Roly Poly is already active, Spawn() dismisses it before spawning a new one. If AutomaticRespawn is enabled in the device properties, this also starts the respawn timer — which may cause an unexpected second spawn. Disable AutomaticRespawn when you want full manual control.

6. Dismiss() respects AutomaticRespawn

Calling Dismiss() while AutomaticRespawn = true will queue a respawn after RespawnDelay seconds. If you want a one-shot dismissal, turn off AutomaticRespawn in the device settings panel before calling Dismiss().

7. The device must be enabled for Spawn() to work

If the spawner is disabled (via Disable() or the editor setting), Spawn() silently does nothing. Call Enable() first if you've disabled the device programmatically.