Items & Mobs

Custom content is declared at the top level, like everything else. An item block gives you an identity-carrying item with the exact lore you write and a tree of NBT data; a mob block gives you a spawnable creature with AI, drops, and handlers. Both are checked: rarities, AI modes, and click filters are closed enums, and a drop referencing an unknown item id is a compile error.

Declaring an item ​

item "aspect_of_the_end" {
    material: "DIAMOND_SWORD"
    name: "<blue>Aspect of the End"
    rarity: rare
    glint: true

    tags: {
        damage: 100,
        meta: { tier: 3, keywords: ["end", "sword"] }
    }

    lore {
        line "<gray>A legendary blade from the End."
        blank
        line "<dark_gray>Soulbound"
    }
}

command "kit" {
    execute {
        give item "aspect_of_the_end" to sender
        send "<green>Kit delivered." to sender
    }
}

The declaration owns four things: identity (material or skull), appearance (name, rarity, glint), the lore you write line for line, and a tags tree of freeform NBT. The lore is what-you-see-is-what-you-get — no sections are assembled for you — and one of the four vanilla rarities (common, uncommon, rare, epic) tints the name. lore { } allows line, blank, and if/loop, the same restricted DSL as scoreboard lines.

# vanilla Skript: the "custom item" is rebuilt inline
# at every give site — name, lore, and enchant glint
# restated each time, drifting apart over time
command /kit:
    trigger:
        give player diamond sword named "&9Aspect of the End" with lore
            "&7A legendary blade from the End." and "&8Soulbound"

item "aspect_of_the_end" {
    material: "DIAMOND_SWORD"
    name: "<blue>Aspect of the End"
    rarity: rare

    lore {
        line "<gray>A legendary blade from the End."
    }
}

command "kit" {
    execute {
        give item "aspect_of_the_end" to sender
    }
}

Identity: custom_id ​

Every declared item is tagged with its id, and the tag survives inventories, chests, and restarts. custom_id(<item>) reads it back as an optional<String> — none for vanilla items, so Step 07 discipline applies:

event PlayerUseItem {
    execute {
        if custom_id(event.item) otherwise "" is "aspect_of_the_end" {
            send "<gray>You used the Aspect!" to event.player
        }
    }
}

custom_item("id") conjures a fresh instance as an expression, and any item value exposes a tags namespace: item.tags.<path> reads and writes freeform NBT, nesting through compounds (item.tags.meta.tier) and integrating with optionals — a missing tag reads as none.

Tags, attributes, and on_click ​

Three optional pieces turn a decorated item into interactive equipment:

• tags { } — arbitrary nested NBT (damage: 100, meta: { tier: 3 }), read and written at runtime through item.tags.*. This is where your own "stats" live — plain data you design.
• attributes { } — real vanilla attributes (speed, max_health, attack_damage, attack_speed, armor, knockback_resistance), applied while the item is held or worn and removed when it isn't.
• on_click(<filter>) { } — a filtered use handler (left, right, any) bound to this item, with player and item in scope. A tag write inside re-renders the lore and flushes back to the hand.

item "crypt_key" {
    skull: "1ae3855f952cd4a03c148a946e3f812a5955ad35cbcb52627ea4acd47d3081"
    name: "<gold>Crypt Key"
    rarity: epic

    tags: {
        uses: 3
    }

    on_click(left) {
        set item.tags.uses to (item.tags.uses otherwise 0) - 1
        send "<light_purple>The key turns... (${item.tags.uses otherwise 0} uses left)" to player
    }
}

(skull: instead of material: renders a player-head with that texture — one or the other, never both; the checker enforces it.)

Declaring a mob ​

item "rotten_scimitar" {
    material: "GOLDEN_SWORD"
    name: "<gray>Rotten Scimitar"
    rarity: uncommon

    tags: {
        damage: 40
    }
}

mob "crypt_ghoul" {
    type: "ZOMBIE"
    name: "<red>Crypt Ghoul <green>${mob.health}<red>❤"
    health: 200
    damage: 25
    speed: 0.3
    ai: melee

    drops {
        item "rotten_scimitar" chance 0.05 amount 1
        item "ROTTEN_FLESH" chance 0.5 amount 2
    }

    on_spawn {
        broadcast "<gray>A ${mob.custom_id} rises from the crypt..."
    }

    on_death {
        if killer exists {
            send "<green>You slew the Crypt Ghoul!" to killer
        }
    }

    on_attack {
        send "<red>The ghoul rakes at you!" to victim
    }
}

The pieces:

• type — the base entity, validated against the real entity-type registry.
• name — live-interpolated: ${mob.health} re-renders on the nameplate as the mob takes damage.
• ai — melee (target, chase, attack), passive (wander), or none (statue).
• drops { } — each roll is item <id> chance <p> amount <n>; ids can be your custom items or vanilla materials, checked at compile time.
• Handlers bind mob, plus killer (an optional<Player> — narrowing required) in on_death and victim in on_attack.

A custom mob is an entity, so the shared entity properties and statements — velocity, glowing, mount, remove entity — work on it alongside its typed mob rows.

Spawning and querying ​

These commands live in the same file as the mob "crypt_ghoul" declaration above — spawning an undeclared mob id is a compile error.

command "ghoul" {
    execute {
        spawn mob "crypt_ghoul" at location(10, 64, 20) as m
        set m.health to m.max_health / 2
        send "<gray>Spawned ${m.custom_id} at half health." to sender
    }
}

command "cleanse" {
    execute {
        loop all_mobs("crypt_ghoul") as g {
            despawn g
        }
        send "<green>The crypt is quiet." to sender
    }
}

spawn mob ... as m binds the new mob to a variable — a Mob value with properties health (rw), max_health (ro), name (rw), location (rw), type (ro), and custom_id (ro). all_mobs("id") lists the living instances; despawn removes one.

Server-wide, the MobSpawn, MobDeath, and MobDamageevents fire for every custom mob — per-mob handlers for the mob's own story, events for global systems:

persistent mob_kills for Player: Integer = 0

event MobDeath {
    execute {
        if event.killer exists {
            set mob_kills for event.killer to (mob_kills for event.killer) + 1
            send "<gold>Kill #${mob_kills for event.killer}: ${event.mob.custom_id}" to event.killer
        }
    }
}

That's a kill tracker in ten lines — persistence from Step 10, optionals from Step 07, and content from this one. Next: packaging systems like it into reusable modules.