Gaming Rules-design note One Hero Engine

One Hero Engine: Magic

MP, casting, sustained spells, and the tested v0.20 core spell list.

MP

Magic in OHE is meant to stay strong without taking over the whole game. I want it to feel useful, dangerous, and worth choosing, but still readable in a short solo session.

Magic User starting MP: 7

Magic User maximum MP increases by 1 at levels 3, 5, 7, and 9.

Casting

Use one of these procedures depending on what the spell is trying to do:

  • Utility spell without meaningful opposition: spend MP and apply the effect
  • Attack spell: roll under the Casting Attribute, adjusted by enemy Guard
  • Control or mental spell: roll under the Casting Attribute, adjusted by enemy Threat or relevant resistance
  • Area spell: make one roll using the strongest relevant opposition in the affected area

Natural 1:

  • increase damage by one Damage Step
  • or improve the non-damage effect appropriately

Natural 20:

  • the spell fails
  • MP is still spent
  • introduce a complication

That keeps spellcasting inside the same roll-under language as everything else. I did not want a separate magical minigame with its own logic.

Sustained spells

A hero may sustain only one spell at a time.

This limit is there to keep the hero from stacking too many ongoing effects at once. I would rather have one meaningful magical state in play than three half-remembered ones.

A sustained spell ends when:

  • the hero dismisses it
  • the hero is Defeated
  • the hero sustains another spell
  • its stated duration ends

Recovery

Short rests do not restore MP.

Long rests restore all MP.

You may sacrifice 2 HP to recover 1 MP, but never below 1 HP.

That trade matters. It lets the Magic User keep going when the scene really needs one more spell, but it should never feel free.

Tested v0.20 core spells

The current spell list is deliberately small. I am trying to test a reliable core before I add breadth.

Offensive spells

Arcane Lance

  • MP cost: 2
  • Action type: Action
  • Target: one enemy or a straight line through two Minions
  • Range: Far
  • Roll required: attack spell using Guard
  • Exact effect: deal Step 3 damage
  • Duration: immediate
  • Sustained: no

Eldritch Bolt

  • MP cost: 1
  • Action type: Action
  • Target: one enemy
  • Range: Near or Far
  • Roll required: attack spell using Guard
  • Exact effect: deal Step 2 damage
  • Duration: immediate
  • Sustained: no

Shadow Grasp

  • MP cost: 2
  • Action type: Action
  • Target: one enemy
  • Range: Near
  • Roll required: control spell using Threat
  • Exact effect: deal Step 1 damage and the target cannot move farther away before the end of its next turn
  • Duration: until the end of the target’s next turn
  • Sustained: no

Radiant Burst

  • MP cost: 3
  • Action type: Action
  • Target: one group in Close or Near range
  • Range: Near
  • Roll required: area spell using the strongest relevant opposition
  • Exact effect: deal Step 2 damage to one Standard, Elite, or Boss, or defeat one Minion on a successful damaging hit
  • Duration: immediate
  • Sustained: no

Defensive and restorative spells

Arcane Shield

  • MP cost: 1
  • Action type: Reaction
  • Target: yourself
  • Range: self
  • Roll required: no
  • Exact effect: gain +1 Soak against one incoming hit
  • Duration: one hit
  • Sustained: no

Bone Armor

  • MP cost: 2
  • Action type: Action
  • Target: yourself
  • Range: self
  • Roll required: no
  • Exact effect: gain +1 Soak
  • Duration: current scene
  • Sustained: yes

Healing Word

  • MP cost: 2
  • Action type: Action
  • Target: yourself or one ally
  • Range: Near
  • Roll required: no, unless an enemy is directly disrupting the casting
  • Exact effect: recover 1d6 HP
  • Duration: immediate
  • Sustained: no

Life Ward

  • MP cost: 2
  • Action type: Action
  • Target: yourself
  • Range: self
  • Roll required: no
  • Exact effect: ignore the next 1d6 damage before Soak
  • Duration: current scene or until used
  • Sustained: yes

Utility and control spells

Compel Truth

  • MP cost: 1
  • Action type: Action
  • Target: one speaking target
  • Range: Close or Near
  • Roll required: control spell using Threat
  • Exact effect: the target must answer the next direct question honestly or refuse to answer at all
  • Duration: one exchange
  • Sustained: no

Invisibility

  • MP cost: 3
  • Action type: Action
  • Target: yourself
  • Range: self
  • Roll required: no
  • Exact effect: you cannot be targeted by ordinary sight alone
  • Duration: current scene or until you attack
  • Sustained: yes

Mage Step

  • MP cost: 1
  • Action type: Action
  • Target: yourself
  • Range: self
  • Roll required: no
  • Exact effect: move one range band without spending a Move action
  • Duration: immediate
  • Sustained: no

Raise Dead

  • MP cost: 3
  • Action type: Action
  • Target: one fallen creature or shaped remains
  • Range: Close
  • Roll required: no
  • Exact effect: create one Standard summoned ally using the summon profile below
  • Duration: one scene
  • Sustained: yes

Summoned ally profile

Use one Standard allied profile:

  • Guard: 0
  • Threat: 0
  • HP: 6
  • Damage: 1d4
  • Soak: 0
  • Traits: one simple attack form matching its fiction

The summon acts after the hero. Only one summoned creature may be active at a time.

Legacy spell ideas — Not Yet Updated for v0.20

The following spell names remain part of the older design material but are not current tested-core spells:

  • Arcane Grasp
  • Arcane Recall
  • Bless (both older variants)
  • Blur
  • Bone Golem
  • Cloak of Silence
  • Counterspell
  • Dazzling Veil
  • Deathgate
  • Death Whispers
  • Detect Magic
  • Divine Light
  • Drain Life
  • Dream Echo
  • Eye of the Void
  • Forbidden Words
  • Ghoul Claws
  • Grave Hunger
  • Lightning Ray
  • Magic Missile
  • Mental Probe
  • Mirror Image
  • Mind Shatter
  • Phantom Blade
  • Primal Roar
  • Sacred Barrier
  • Smite
  • Soul Leech
  • Spell Echo
  • Spirit Sense
  • Thought Thief
  • Tranquil Mind
  • Umbral Chains
  • Whispering Madness

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