Give an ability a cost

Three pieces: a bar to spend from, an ability that spends it, and optionally a toggle that drains it while it is on.

The bar

A neoorigins:resource shows on the HUD and refills on its own:

// data/mypack/origins/powers/mana.json
{
  "type": "neoorigins:resource",
  "name": "Mana",
  "min": 0, "max": 100, "start_value": 100,
  "regen_rate": 2, "regen_interval": 20,
  "hud_render": { "label": "Mana", "color": "#55AAFF" }
}

An ability that spends it

active_ability reads resource_cost and resource_cost_amount. With less than 25 mana the key does nothing, and no cooldown starts:

// data/mypack/origins/powers/surge.json
{
  "type": "neoorigins:active_ability",
  "name": "Surge",
  "cooldown_ticks": 40,
  "resource_cost": "mypack:mana",
  "resource_cost_amount": 25,
  "entity_action": { "type": "neoorigins:dash", "strength": 1.5 }
}

active_teleport, active_phase, active_place_block, ground_slam, tidal_wave, shadow_orb, tame_mob and summon_minion read the same two keys: see Who reads the cost keys.

Types that don’t read resource_cost

Most other actives (active_dash, active_bolt, active_swap, …) ignore it. Charge those by hand: gate the power on a neoorigins:resource condition, and spend from a power_activated listener, which only fires when the ability actually went off:

// data/mypack/origins/powers/lunge.json
{
  "type": "neoorigins:active_dash",
  "power": 1.8,
  "cooldown_ticks": 60,
  "power_condition": {
    "type": "neoorigins:resource",
    "resource": "mypack:mana",
    "comparison": ">=",
    "compare_to": 30
  },
  "power_condition_mode": "ALLOW"
}

// data/mypack/origins/powers/lunge_cost.json
{
  "type": "neoorigins:action_on_event",
  "event": "power_activated",
  "power": "mypack:lunge",
  "hidden": true,
  "entity_action": {
    "type": "neoorigins:change_resource",
    "resource": "mypack:mana",
    "operation": "add",
    "change": -30
  }
}

Keep compare_to and change in step. change_resource clamps at the bar’s min, so a cost larger than the gate would empty the bar rather than refuse the ability.

A toggle that drains while it is on

Every toggle type takes the same hunger_cost / resource_cost / resource_cost_amount keys as an upkeep, charged every upkeep_interval ticks. When the bar can’t cover a charge, the toggle switches itself off:

// data/mypack/origins/powers/levitate.json
{
  "type": "neoorigins:creative_flight",
  "resource_cost": "mypack:mana",
  "resource_cost_amount": 3,
  "upkeep_interval": 20,
  "upkeep_condition": { "type": "neoorigins:creative_flying" }
}

The upkeep_condition charges only while the player is actually flying. Full rules, including how a toggle with no key behaves: Toggle upkeep.

An aura that drains while it runs

effect_over_time charges its upkeep once per pulse, in every mode, rather than on an upkeep_interval. An active (keybind) aura that can’t pay switches itself off; a plain passive aura skips that pulse and tries again on the next one. This passive healing field costs 1 food point (saturation first) every 2 seconds, and stops healing once food and saturation are both empty:

// data/mypack/origins/powers/mending_field.json
{
  "type": "neoorigins:effect_over_time",
  "activation": "passive",
  "interval": 40,
  "hunger_cost": 1,
  "entity_action": { "type": "neoorigins:heal", "amount": 1 }
}

The full rules (all-or-nothing charges, upkeep_condition, keyless toggles) are in Costs & upkeep.

Which pattern to use

You want	Use
A one-off cost per key press	resource_cost / hunger_cost on active_ability
A cost on a type that has no cost keys	The resource condition plus change_resource pattern above
A cost while a toggle stays on	The toggle upkeep keys
A cost per aura pulse	The cost keys on effect_over_time