A Brief Spell of Madness: A New Twist on GURPS Magic

by Christopher M. Dicely

Art by Dan Smith and Colored by Keith Johnson


This article lays out a variant system of GURPS magic in which the practice of magic poses great risk to the sorcerer. In can be used in a number of settings: for instance, it could be used in a "secret magic" setting, especially one in which magic was typically a dark force (like GURPS Horror or GURPS Cthulhupunk). It could also be used in a medieval fantasy setting, where it would explain why wizards might be widely feared by common folk and reluctant to share the secrets with any but apprentices carefully chosen both for natural talent and strength of will.

Basic Rules

No special advantage (i.e., Magery) is required to cast spells in this system. The curious student who finds a book with real spells buried in the stacks at her college library might learn to cast some of those spells, but only at great personal risk.

All characters have a level of Magic Stress, which represents the strain on their mind from recent magical activity. Magic Stress starts at zero, increases with spellcasting, and decreases with rest, as explained in these rules.

All characters also have a level of Stress Tolerance, which rates their resistance to the psychological effects of increasing Magical Stress. The base value of Stress Tolerance is two, but this can be modified by the Magic Sensitivity and Magic Resistance advantages.


A Brief Spell of Madness: A New Twist on GURPS Magic

The Magical Aptitude advantage no longer exists. However, two new advantages for spellcasting replace it: Magic Sensitivity and Magic Power. In addition, the Magic Resistance advantage is significantly different than the standard version.

Magic Sensitivity (5 points per level)
Your mind is unusually sensitive to the underlying structure of the universe. This allows you to be more adept than most when using magic, however, it also makes you more sensitive to the shock of spellcasting. Each level of Magic Sensitivity gives you a +1 to all spell skills, but halves your Stress Tolerance. Magic Sensitivity cannot be combined with Magic Resistance or with Magic Power.

Magic Power (5 points per level)
You have a mind that is "wired better" for coping with the exposure to mystical underpinnings of reality. This gives you the ability to wield a greater amount of magical power at any given level of personal risk. Each level of Magic Power gives you a +1 to Stress Tolerance, and a +1 to IQ when determining whether a spell is powerful enough to require a special modifier to the Fright Check when casting. Magic Power cannot be combined with Magic Sensitivity, but it may be combined with Magic Resistance.

Magic Resistance (5 points per level)
You are unusually resistant to all of the effects of magic. For each level of this advantage, any spells which have you as the target give the caster a -1 penalty to skill, any resistance rolls you make against spells have a +1, and you receive a +1 bonus to your Stress Tolerance. On the downside, however, you are rather inept at manipulating magic, giving you a -3 penalty to all spellcasting rolls for each level of this disadvantage. Note that this penalty applies only to spellcasting rolls, not to spell skill levels for other purposes (e.g., prerequisites for other spells). Magic Resistance cannot be combined with Magic Sensitivity; it can be combined with Magic Power.

Casting Spells

When you attempt to cast a spell, you make the usual roll to cast the spell, with a penalty of -1 per point that the casting cost exceeds your (Will + Magic Power), and the effects of the spell are resolved normally. Then, the casting cost of the spell being cast is added to your Magic Stress. Finally, you make a Fright Check, with a penalty equal to your Magic Stress divided by your Stress Tolerance, rounded down, and, if the spellcasting roll failed, a additional penalty of one for each point by which it did so.

Maintaining Spells

Whenever you need to pay the maintenance cost for a spell, you follow the same procedure as with spellcasting, except that there is no roll to cast the spell.

Recovering Energy

For each full night of sleep, a character reduces his Magic Stress by a number of points equal to IQ modified by Strong/Weak Will and then halved, +1 per level of Magic Power. This number is known as his Recovery Number.


Energy from a powerstone aids in spellcasting. Energy drawn from a powerstone is not assessed against your Magic Stress, although you still must make a Fright Check based on your current Magic Stress even if all of the energy for your spell comes from the stone.

Ceremonial Casting and Group Magic

These special types of spellcasting use the rules in the Basic Set or Magic, with the exceptions noted here.

The only restriction on what casters may join a circle and contribute energy is that every member of the circle must know the spell. There is no minimum skill level, nor is there any limit on the amount of energy each caster may contribute. The caster with the lowest skill always makes the skill roll, and every caster gains Magic Stress and makes a Fright Check based on the amount of energy they contribute. In the event of a spell failure, the margin of failure penalizes every caster's Fright Check, not just the one who makes the roll.

Spectators are allowed (and those who know the spell may opt to be spectators rather than members of the circle). Spectators are treated exactly as members of the circle, except that their skill levels are not included when determining which caster has the lowest skill and they may each contribute only a single point of energy to the casting. The only limit to the number of spectators participating is that the amount of energy from spectators cannot exceed the skill of the least-skilled caster in the circle times the number of casters in the circle.

Each person present (within sight or 10 yards of any member of the circle or participating spectator) during the casting who is neither a member of the circle nor a participating spectator imposes a -1 penalty to the final skill roll. Each person present who is actively opposed to the spell being cast imposes the same penalty and additionally adds 5 points to the casting cost of the spell.


As in the standard GURPS Magic system, a caster's effective skill when casting an enchantment is equal to the lower of his skill with the Enchant spell or the spell being enchanted into the item.

Instead of being equal to the skill of the caster, the Power of a magic item has a base value of 10. This is increased by one point for each point by which the skill roll to create the item is made. The effects of a failed skill roll vary by the type of enchantment being used.

The enchantment methods in this system share the names of those in the standard system, but have been significantly altered.

Quick and Dirty Enchantment

This method of enchantment is treated as any other use of ceremonial magic, described above. The casting time in hours is equal to the energy cost of the enchantment divided by 100, rounded up. If the skill roll to cast a Quick and Dirty enchantment fails by less than five points, the item is still enchanted, but has a reduced Power. From the base Power of 10, subtract the number of points by which the roll failed. If the roll fails by more than five points, the enchantment fails entirely.

Any item produced by Quick and Dirty Enchantment may have flaws. To determine if it does, once the item is created, the GM should make a roll against the item's Power. If this roll succeeds, the item has no flaws. If it fails, it should have 1d/2 "warps" -- minor flaws which affect when or how it can be used. The descriptions of minor Powerstone flaws in GURPS Magic are a good starting point, although you will want to make sure the flaw makes sense for the item. If it critically fails, it will have 1d-1 warps plus one serious flaw - it either functions as a different spell or has some kind of deleterious side-effect on the user, for instance. Flaws will not be apparent without casting Analyze Magic on the item.

Slow and Sure Enchantment

This method of enchantment is also a form of ceremonial casting. It is much safer than the Quick and Dirty method, at the cost of increased time. An enchantment by this method usually takes multiple days (each day consisting of 8 hours of casting the enchantment, with the remainder available for other activities like sleeping, eating, etc.).

Each day of casting, each caster in the circle may contribute any amount of energy up to his Recovery Number plus any energy drained from a single powerstone during the day. At the end of the day's casting, the caster makes a Fright Check as if that energy had been spent on a completed spellcasting, although the actual skill roll is not made until the casting is complete.

The final spellcasting roll for the enchantment is made at the end of the day on which the energy cost of the enchantment is met, and the final Fright Check for each caster is made after that roll, with the usual modifiers if the roll fails.

Spectators cannot assist with a Slow and Sure enchantment, only skilled casters working as full members of a circle may do so. If the final casting roll for a Slow and Sure enchantment fails, the effort and any materials, including the item being enchanted, are wasted. If the item already had an enchantment on it, the item and the original enchantment may survive: roll against the Power of the pre-existing enchantment to see if it does. If there are multiple pre-existing enchantments, roll against the weakest to see if all of them survive.


The Alternate Magic Ritual Rule in the sidebar of p. M7 is used instead of the standard ritual rules which reduce the required ritual with increasing skill. In addition, the caster can halve the casting time for each -5 penalty taken to skill.

New/Modified Spells

All Magery prerequisites are replaced with prerequisites based on the Thaumatology skill. A prerequisite of Magery becomes "Thaumatology 12+", a prerequisite of Magery 2 becomes "Thaumatology 15+", and a prerequisite of Magery 3 becomes "Thaumatology 18+".

Otherwise, most spells written for the standard GURPS magic system can be used in this system without further modification. However, a few spells require special attention. In particular, spells whose effects are designed around the relation between fatigue and magic energy in the standard system need to be re-examined to work well with this system.

Healing Spells

Lend Strength


Allows the caster to restore the subject's lost fatigue, at the expense of fatiguing himself. For each point of fatigue restored to the subject, the caster takes one point of fatigue.
Cost: 1; allows caster to transfer as many points of fatigue as he desires.
Prerequisite: Thaumatology 12+; or the Empathy advantage.

Recover Strength


The subject of this spell (which may be the mage himself) recovers fatigue faster while under the influence of this spell. The subject must be resting quietly; he may not, for example, cast spells or even maintain spells that require concentration.
Cost: 2 for the subject to recover one point per 5 minutes of rest, 5 for one point per 2 minutes, 10 for one point per minute; same to maintain.
Time to Cast: 1 minute.
Duration: 10 minutes.
Prerequisite: Lend Strength.

Share Strength

This spell is changed to Share Power. See below.


Share Power


Allows another caster to serve as a conduit of energy for another mage's spellcasting. The subject of this spell is another character that can draw energy from the mage for the purpose of casting a spell. The subject may draw the energy the following turn as long as he is casting a spell; if the spell would not be completed on that turn, he may "hold" the energy to use when the casting is complete. The casting cost, skill roll, and Fright Check for this spell are made once the subject decides how much energy he will draw, up to a limit of the caster's Recovery Number (if he chooses a greater amount, he only gets the maximum and provides the rest himself!). Duration: Energy must be drawn in the turn following casting, cannot be maintained.
Cost: Twice the amount of energy drawn by the subject.
Prerequisite: Thaumatology 12+.

Article publication date: September 15, 2000

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