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A Simple Magic System for GUMSHOE

Sat 12 November 2022 | Game Design

This is an simple set of rules for casting magic and creating magic spells in GUMSHOE roleplaying games.

In this system, Magic is a general ability. You may learn a number of spells equal to your Magic rating. There are six categories of spells, and a spell’s category determines how many points it costs to cast.

When you learn a spell, name it, choose its category, and describe it’s effect briefly, in three words or less. The GM will work with you to establish the spell’s approximate limits, or may declare that the spell is inappropriate for the game and suggest an alternative. A few example spells appear in the list of categories below.

Glamour: 1 point

These spells, though simple, were crucial for our distant ancestors at the dawn of humanity.


  • Conflagration: ignite a flame
  • Pacification: calm an animal
  • Perception: see in darkness
  • Ventriloquism: throw your voice
  • Seasoning: improve a meal

Prestidigitation: 2 points

These spells involve brief, gentle physical force, making them useful at both burglaries and parties.


  • Cleansing: clean and dry
  • Telekinesis: retrieve something small
  • Locksmithing: open a lock
  • Misfire: jam a pistol

Channeling: 3 points

These spells release a strong surge of energy, and might be either your worst or best options in a fragile situation.


  • Thunderbolt: smite with lightning
  • Propulsion: push forcefully
  • Zephyr: call the wind

Illusions: 4 points

It turns out that altering someone’s perceived reality is almost as hard as altering their actual reality.


  • Obfuscation: protect from scrying
  • Concealment: disappear from view
  • Impersonation: resemble someone else
  • Misdirection: conceal another spell
  • Forgery: simulate a document

Transformation: 5 points

If you point at an ounce of lead and say “gold” with enough sincerity, the cosmos will give you the benefit of the doubt.


  • Lycanthropy: become a wolf
  • Meteorology: change the weather
  • skin like stone
  • slick with ice

Divination: 6 points

Any fool can break the universe; only a master can comprehend it.


  • glimpse the past
  • guide toward something
  • question the dead

The above costs are minimums. You may wish to overspend on a spell in case of resistance, which occurs when a new spell would conflict with an already-active spell. In this event, the caster of the new spell rolls a die and adds the number of Magic points they spent. If the result is 3 points higher than the cost of the original spell, the new spell wins.

Instead of casting an opposing spell, you may resist an active spell with your raw magical talent. In this case, you roll a die and add at least 1 Magic point, then compare to the cost of the original spell as before.

You may also wish to overspend to prevent detection. Others can sense the use of magic if their Magic rating equals or exceeds the cost of your spell.

If your Magic rating is 8 or better, you are a practitioner, and your spells are harder to resist. Anyone attempting to resist your spells must beat your spell cost by 5 points.

Spell effects are temporary, because the universe will seek to restore its balance. When a spell produces a brief burst of energy, the side effects will remain; for example, if you burn a hole in a curtain with magical flame, the hole will remain after the fire goes out. Other magical effects typically revert within an hour.

When it's necessary to determine the game effects of a spell (how many points of Health do you lose if someone casts "burn with fire" on you?) discuss with the gamemaster. Use other established game effects, such as weapons or special abilities, to provide guidelines.

This work is based on the GUMSHOE SRD (found at, a product of Pelgrane Press, developed, written, and edited by Robin D. Laws with additional material by Kenneth Hite, and licensed for our use under the Creative Commons Attribution 3.0 Unported license ().

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