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End-to-End Walkthrough: Your First Custom Mob

A complete example touching six systems: ability → item → mob → spawner → loot → quest. No prior knowledge required. Each step is copy-pasteable.

What we're building

A Forest Goblin that: - Poisons players on hit - Carries a custom weapon - Drops a crafting material - Is spawned by a world spawner - Is tracked by a quest: "Kill 10 Forest Goblins"

Step 1 — Create the ability

The goblin's on-hit poison. File: plugins/rpg-core/abilities/goblin.yml

goblin_poison_strike:
  Name: "Poison Strike"
  Description:
  - "&7A venomous bite."
  AbilitySequence:
  - apply_status{id=poison, level=1, duration=100, target=target}

This ability applies the built-in poison status effect to whatever the goblin just hit. No cooldown needed — mob abilities gate themselves via their trigger interval.

Reload: /rpg reload

Step 2 — Create the item (optional — gives the goblin a weapon)

File: plugins/rpg-core/items/goblin.yml

goblin_dagger:
  MinecraftItem: stone_sword
  Type: SWORD
  DisplayName: "&2Goblin Dagger"
  Rarity: "&f&lCOMMON"
  Lore:
  - "&7Crude but sharp."
  Stats:
    damage: 12
    strength: 5

This item shows in the goblin's hand and contributes its damage stat to attacks.

Reload: /rpg reload

Step 3 — Create the mob

File: plugins/rpg-core/mobs/forest.yml

forest_goblin:
  MinecraftMob: zombie
  DisplayName: "&2Forest Goblin"
  Health: 150
  Damage: 10
  Armor: 0
  AI:
    profile: aggressive
    aggression-range: 14
    attack-range: 2
    leash-range: 30
    leash-action: return
  Equipment:
  - HAND goblin_dagger
  Abilities:
  - goblin_poison_strike{} ~onHit
  LootTable:
    attribution: weighted-by-damage
    roll-mode: per-player
    coin-drop: { min: 5, max: 20 }
    rolls:
    - { item: goblin_ear, chance: 40.0, min: 1, max: 1 }
    - { item: goblin_dagger, chance: 4.0, min: 1, max: 1 }

Also add the drop item to your items file:

goblin_ear:
  MinecraftItem: rabbit_foot
  Type: MATERIAL
  DisplayName: "&2Goblin Ear"
  Rarity: "&f&lCOMMON"
  Lore:
  - "&7Proof of a goblin kill."

Reload: /rpg reload

Test spawn it: /rpg mob spawn forest_goblin

You should see a zombie named "Forest Goblin" that poisons you when it hits you, and drops ears + coins on death.

Step 4 — Create a spawner

Place a spawner block in-world (vanilla spawner or any block you designate), then register it:

/spawner create goblin_spawner
/spawner set goblin_spawner mob forest_goblin
/spawner set goblin_spawner radius 16
/spawner set goblin_spawner max-alive 5
/spawner set goblin_spawner cooldown 200
/spawner set goblin_spawner mode continuous

Now goblins spawn automatically near that block. See Spawning for full options.

Step 5 — Create the quest

File: plugins/rpg-quests/quests/starter.yml

goblin_slayer:
  DisplayName: "&2Goblin Slayer"
  Description: "The forest goblins are getting bold. Thin their numbers."
  Category: combat
  Repeatable: false
  Objectives:
  - type: kill_mob
    mob: forest_goblin
    count: 10
    display: "Kill Forest Goblins"
  Rewards:
    Currency: 500
    SkillXp:
      combat: 200
    Items:
    - { item: healing_potion, amount: 3 }

Reload: /rpg reload

Players accept the quest via /quests (or an NPC with Quest: goblin_slayer in its config). Every forest_goblin kill increments their objective counter. At 10 kills, the quest auto-completes and grants the reward.

How the systems connect

goblin_poison_strike (ability)
        ↓
    on ~onHit trigger (ability system)
        ↓
    apply_status{id=poison} (status effect system)
        ↓
    victim takes periodic poison damage (damage pipeline)

forest_goblin (mob)
        ↓
    killed by player
        ↓
    LootTable rolls (loot system) → goblin_ear drop + coins
        ↓
    kill_mob objective increments (quest system)
        ↓
    at 10 kills → quest reward granted (economy + XP)

Next steps

  • Add more mob abilities (see Abilities for all effect types)
  • Gate a weapon drop behind a rarer roll (chance: 1.0)
  • Make the quest require a specific region (Regions)
  • Give the goblin a boss variant with higher health and a ground slam ability
  • See the full Cookbook for more content examples