GURPS Magic GM's Cheat Sheet (B146)


Concentration for N turns.
then Roll 3d6 at start of next turn, against spell skill. For missle spells: Roll 3d6 in next turn against throw skill or DX-3. Spell may be maintained into the future.

Availability / Ritual
You may not cast two spells at once!
For Information spells: most are limited to once per day per party (expect seeker spells).
Skill <=11: move hands and feet, speak firmly.
Skill 12-14: make gesture, and speak quietly.
Skill 15-17: finger gesture, and speak a word or two.
Skill 18-20: finger gesture, or speak a word or two.
Skill 21-24: none needed.

Whatever the spell says.
Skill <=11: double the length.
Skill >=21: half the length (round up).
Skill >=25: one forth the length (round up).
Missle spells can add extra concentration for extra power.
If distracted, spell casters must make a Will-3 to continue.
If injured, the effective skill drops by damage points.
Caster can choose to abort, an not lose energy, but restart from scratch.

Caster can choose to loose HT or ST for this.
Area spell: use 1 point per hex radius of effect.
Skill >=15: reduce by one points.
Skill >=20: reduce by two points.
Skill >=25: reduce by three points.

Roll Target/Modifiers
Info spell: roll in secret and lie on crit failure.
Subtract one per HT used to cast the spell.
Reg spell: -1 per hex range (at end of concentration).
Reg spell: -5 if caster can not touch or see target.
Other active spells: -1 or -3 if concentraiting on another spell.

Maintained into the Future
Spells can be ended early by using a point of energy.
Energy cost to continue a spell is the same as to cast it.
Energy savings due to high skill are also applied to maintaining.
This may cause "free" spell maintenance.
Concentration is usually not need, but may be (for control).
Distraction requires a roll against Will-3 to continue.
Spells can not be maintained while sleeping!


crit fail
Roll on the "crit fail" table, or GM's call: anything is possible. (Magic is fickle)
If spell uses any energy: loose 1 pt of HT or ST.
Spell works normally. Lose normal engergy; see normal effect.
crit succeed
Resisted spell is not resisted this time.

Normal Mana:
must have Magical Aptitiude to cast spells
Only covers skills up to 25.
Ceremonial and Group Magic not covered (yet).
Magical items not covered.

Spell Classes


Spell Colleges

Animal (B155)
Communication and Empathy (B155)
Light/Darkness (B163)
Mind Control (B164)

Seek Modifiers (B151)

-1 for each "known" item to be ignored.
up to half-mile distant: -1
up to mile: -2
up to 3 miles: -3
...more in book...

Critical Failure (3d6)

3Spell fails entirely; caster takes 1d damage
4Spell is case on spell caster
7Spell produces only a whining noise and an awful odor of brimstone.
8Spell affects someone or something (randomly or GM's selection) other than its target.
9Spell fails entirely; caster takes 1 point of damage.
10Spell fails entirely; caster is stunned (IQ roll to recover).
11Spell produces nothing but a loud noise and a flash of colored light.
12Spell produces a weak and useless shadow of its intended effect.
13Spell produces the reverse of the intended effect.
14Spell has the reverse of the intended effect, on (randomly) wrong target
17Spell fails entirely;
18Spell fails entirely;

This "cheat sheet is still under develop- ment, and some parts are missing entirely, or need to be filled in!


Skill effects
Crit fail table
General review
Spell classes (?)
Seek mods

Ranges for Spells

Stone Missles: SS13 Acc+3 1/2D 50, max100
Lightning SS13 Acc+1 1/2D 25 max 50
Fireball: SS13 Acc
Ice Sphere: SS13

Random Notes

Max protection from any spell is 5.

Minimum Grimoire

  1. Name
  2. Skill Level
  3. Energy
  4. Effect Summary
  5. College
  6. Range
  7. Duration
Each player must know these things, at a minimum, for each spell their character knows.

Printing notes: Different browsers may print out this page differently. It may not fit on one page. I suggest: 10pt font, 0.2in margins.
Written by: Joshua Levy based on information in GURPS Basic by Steve Jackson Games. (Bnnn) refer to Basic GURPS pages.


If critical success: no resistence attempt.

Otherwise a "quick contest" (B___)

Roll against IQ, ST, DX, or HT, depending on the spell.

Add weak or strong will.

Add magic resistence, doubled for area spells.

Resisted spells still use energy!


Spells are Mental/Hard or Mental/Very Hard skills.

Magical aptitude is an advantage which comes in levels.

IQ+MA = IQ for purpose of learning spells.

Eidetic memory gives +1 or +2 (only) to IQ for learning spells.

Many spells have prerequisites!