Lifeline — health, damage & respawn kit

Drop-in health for anything that can get hurt (players, enemies, breakable props), with damage zones, heal zones, projectiles, respawning, events for your own scripts, and a large wardrobe of looks: 13 health bar styles, 7 damage-number styles (4 presets) and 5 mix-and-match hit effects, all switched by changing one field. Multiplayer-safe: only the peer that owns an entity decides what happens to its health.

Installing it into your world

The package is called Lifeline — asset Lifeline.package, guid 7b85ce05-3903-4374-b654-2d4ffea295a5, MIT licensed. (Its showcase world is Lifeline — Health, Damage & Respawn Kit.)

One install, any of these ways:

• From the ZeroMind library in the editor — search for health or Lifeline and install the Lifeline package.
• By guid, from the engine shell:

  zero zeromind installAsset 7b85ce05-3903-4374-b654-2d4ffea295a5
  

• From Luau:

  tools.use("zeromind", "preview",     "7b85ce05-3903-4374-b654-2d4ffea295a5")  -- what it would write
  tools.use("zeromind", "installAsset", "7b85ce05-3903-4374-b654-2d4ffea295a5")  -- do it
  

• From an agent: zeromind.install { guid = "7b85ce05-3903-4374-b654-2d4ffea295a5" }.

It lands in your /source as Lifeline.package/, so after installing, every piece resolves by that name: Lifeline.Health, Lifeline.LifelineHUD, Lifeline.DamageZone, Lifeline.HealZone, Lifeline.Projectile, Lifeline.ProjectileLauncher, Lifeline.SpawnPoint, and require("Lifeline.api") / require("Lifeline.bars"). Nothing in it is world-specific — you bring the entities. Run zeromind.update later to pull new versions.

Five-minute start

1. Give things health. Add Lifeline.Health to the player body on your scene's PlayerPrototype, and to any enemy or prop. Put enemies and props on synced entities (entity.spawnSynced) so every player sees the same health.

body.component.add("Lifeline.Health", { maxHealth = 100, regenRate = 5, maxShield = 25 })
crate.component.add("Lifeline.Health", { maxHealth = 40, onDeath = "remove" })

2. Show it. Add Lifeline.LifelineHUD to one plain (non-synced) entity in the scene. Every peer runs its own copy.

entity.spawn("HUD").component.add("Lifeline.LifelineHUD", { playerBar = "hearts", worldBar = "overhead" })

3. Hurt and heal. Add a zone to any entity. It's a box of sizeX × sizeY × sizeZ around the entity and moves with it.

lava.component.add("Lifeline.DamageZone", { sizeX = 4, sizeZ = 4, kind = "fire", amount = 5, mode = "perSecond" })
spikes.component.add("Lifeline.DamageZone", { kind = "spikes", amount = 25, mode = "onEnter" })
pad.component.add("Lifeline.HealZone", { amount = 10, interval = 0.5 })

4. From code.

local Lifeline = require("Lifeline.api")
Lifeline.damage(target, 20, { kind = "fire", source = attacker, crit = false })
Lifeline.heal(target, 15)
Lifeline.fire { origin = muzzlePos, direction = aim, damage = 15, source = shooter }  -- projectile
Lifeline.on("died", function(e) print(e.target, "died to", e.kind) end)

5. Respawn. Dead players come back after respawnDelay seconds at a random free Lifeline.SpawnPoint (or at the scene's PlayerSpawn if you haven't placed any), with full health and a moment of spawn protection.

That's it. The scenes.main showcase in this world uses every piece.

What happens on death (onDeath, per entity)

Health fields (most useful)

maxHealth, health, maxShield/shield (soaks damage first), regenRate + regenDelay, shieldRegenRate + shieldRegenDelay, invulnerabilityTime (i-frames after a hit; damage-over-time ticks ignore it), invulnerable (god mode → "IMMUNE"), armor (flat reduction → "BLOCKED"), respawnDelay, spawnProtection, displayName, team, barStyle (bar drawn over this entity, none hides it), bossBar (show the big boss bar when near), bodyHeight/bodyRadius (bar placement and hit volume), killBelowY. Read-only: isDead, deaths.

Events

Lifeline.on(name, fn) fires on every peer for damaged, healed, blocked, died, respawned, or "*" for all. The payload is { event, target, amount, shieldAmount, kind, source, crit, health, shield, maxHealth, reason, origin, pos, isPlayer, name }. It returns a connection with :Disconnect().

Each Health component also exposes typed events: entity.component.get("Lifeline.Health").events.died:connect(fn).

Styles: change one field

On LifelineHUD (or at runtime per player with Lifeline.setStyle { bar = …, worldBar = …, number = …, feedback = … }):

• Bars (playerBar, worldBar, Health's barStyle): classic (lost chunk drains away), segmented, ring, hearts (half hearts, shield hearts, heartbeat at low HP), boss, overhead, minimal, stacked (shield on health), scifi, fantasy, cartoon, pixel, orb.
• Numbers (numberStyle): classic (pop / shaky crit / green heal / IMMUNE-BLOCKED), combo (hits on one target add up into a running total), comic, minimal.
• Feedback (feedback, any mix): flash shake vignette heartbeat direction, or all / none.

Multiplayer & anti-cheat

Health fields are Sync. Only the entity's owner mutates them, and the relay refuses writes from anyone else — so one player cannot set another player's health from their own machine.

• Hit something you own (your avatar, or a prop your peer took) — it changes on your machine and the new value goes on the wire. Every other peer draws exactly that number: health bars, numbers and death screens all read the same synced field.
• Hit something another player owns — Lifeline.damage doesn't decide anything. It sends a request to that entity's owner over multiplayer.send, and the owner validates it before applying. Lifeline.setDamageFilter(function(comp, amount, info, fromPeer) ... end) is where that validation goes: return the amount to allow (clamped if you like), or 0 to refuse. fromPeer is set only when the hit arrived from another peer's request.
• Zones run on every peer but act only on entities that peer owns, so a player in a fire zone is burned exactly once, by their own machine. A player's damage events are broadcast by the owner, so remote players see the same flash, numbers and score hooks.
• Events (Lifeline.on) fire on every peer — same channel the kit uses for its own visuals.

The honest limit: the engine's model is that the owning peer is the authority for its own entities. That is what stops other players from touching your health, and it is what this kit is built on. It does not, by itself, stop a modified client from lying about its own health (a hacked client could ignore a fire zone). If your game needs damage that a cheating client can't dodge, run the damage on a peer you control and funnel it through setDamageFilter — the filter runs on the owner, so it's the place to require proof, rate-limit, or refuse anything that doesn't match your own simulation.

Other hooks

Lifeline.kill, Lifeline.revive, Lifeline.get(target), Lifeline.all(), Lifeline.isAlive, Lifeline.setSpawnPicker(fn(comp, points) -> entity), Lifeline.kinds (damage kinds → colour/label, add your own).

Contents

Health, DamageZone, HealZone, Projectile, ProjectileLauncher (player blaster on a key, or an auto turret), SpawnPoint, LifelineHUD components, plus the api, bars, numbers, feedback and zone modules.