Ars Arcana Blog: Spell Points, Slots, and Abilities

Ars Arcana Blog

2.4: Spells: Points, Slots, and Abilities

Travis Joseph Rodgers

Do spellcasters in your game use spell points, spell slots, or can they call upon spells like other abilities (like climbing, throwing, and hacking)? Here are three potential problems your magic system will have to deal with and three approaches to solving those problems, with strengths and weaknesses of each approach considered.

Part I: The Approaches

These three approaches may not be exhaustive, but they do a good job of capturing the typical range of options one might see in an RPG. They are differentiated by the frequency one can cast and the relative customizability of the power of a “readied” spell.

Spell Points (SP)

Pool of points. Each spell has a cost. More points for more powerful spells. Systems: MERP, Role Master.

E.g., Merlin and Magic Martha both cast “flame bolt” spell. Merlin easily pumps a dozen spell points into it, making it devastate his opponents. Martha fumbles through it, doesn’t have many spell points to spare, and ekes out a wimpy little torch.

Spell Slots (SS)

Spell slots, based on spell level. D&D.

E.g., a fireball is a third level spell. Flaming hands is a first level spell. Fireball is (essentially) a more powerful version of flaming hands.

Spell Abilities (SA)

Set spells and abilities. The Warlock in D&D.

E.g., Spell-like abilities for many creatures or spells for Warlocks in DnD. They can cast a set number per day or have a few different ones they can use as frequently as they desire.

Part II: The Problems

To what extent these things count as problems is likely relative to the game and setting. Problems can be overcome, or they can be balanced by other cool things going on in one’s game/system. So the claim is not that these are damning problems that must be avoided at all costs.

Depleted Points (DP)

Your spell caster has just used their final spell for the day, either by depleting their pool, using their final spell slot, or reaching the maximum uses per day. Now your spellcaster is no longer a spellcaster.

System Nuance (SN)

When your character uses 99% of their capacities in the game, the character checks in manner X. But when the character casts a spell, the character does so in manner Y. Spells, in brief, have different systems of resolution from other actions in most games. For instance, in AD&D, attacks are made on 1d20 and can be done as frequently as you can move. Spells take different amounts of time, some succeed automatically, and they (often) be exhausted.

The Toggle (TT)

In order to combat the SN problem, some steer toward simplicity, others toward complexity. Embracing simplicity means coming up with a magic system that diverges as little as possible from the main resolution mechanic of the system. Making that happen presents problems (it’s hard to do). Embracing complexity brings its own problem, threatening (or promising?) to become its own mini-game within the game.

Part III: Strengths and Weaknesses

The DP Problem

The SA approach with unlimited spell uses solves the DP problem by never having it come up.

The SS approach fares arguably the worst, because even creating flexibility is difficult.

The SP approach creates an incentive system; save your big spells for when they’re needed, but it also faces a scaling problem. Suppose a spell like Magic Missile is a 1-point spell at its weakest (standard form). Suppose a caster receives 3 SP per level. A level 10 spell caster could save SP until a boss battle and unleash a spell 30x more powerful than a Magic Missile. That’s like 30*(2-5), or harder than almost any level 10 character could hit. That might be a problem for balance.

The SN Problem

The SP approach probably fares worst here, as all spells become customizable in ways other skills just aren’t. You can’t “save up” your hacks and then hack really well, for instance.

The SS approach makes spells like other abilities in one way – they CAN be checked in the same way. But they have very different descriptions, etc.

The SA approach offers flexibility. Spells could be just like every other check, or they could be utterly their own thing. That flexibility is arguably a benefit, as some games might WANT to have spellcasting its own mini-game.

The Toggle Problem

Toggling is a problem and an opportunity for all games and systems. It’s not clear that any system faces a special advantage or drawback to meeting the TT problem.

Game Imbalance

If the SN is solved by moving toward complexity and making magic its own game, the threat is that your game requires spellcasters, relegating others to spell book holders (like spear-holders to heroes). Indeed, this is probably the single greatest “problem” (or opportunity) for magic in a system. If magic is required, then players should be aware of that. If magic is common and unbalancing, then players should know that. And if magic is rare, players should know that. In fact, whatever the role of magic, players should all be aware of the rules and the feel.