Willpower Magic System


This magic system is an attempt to remove the aspects of the standard GURPS magic system that I don't much like. It uses some ideas from S. John Ross's Unlimited Mana magic rules.

This document describes the operation of normal "wizardly" magic. Clerical Magic is described separately.

Basic Principles

The guiding principles of this magic system are:

Learning Spells

Magical Aptitude (Magery)

The Magical Aptitude advantage is treated simply as a group skill bonus for spell (and other magic) skills. It is not required to cast spells, though it is required as a prerequisite to learn some of the more complicated spells (as given in standard GURPS books). Since it is not an inborn talent that distinguishes mages from non-mages, the advantage is not synonymous with the term "Magery".

Magical Aptitude costs a flat 10 points per level, ignoring the usual extra 5 points associated with the first level (going from non-mage to mage). The Magical Aptitude skill bonus for Thaumatology still applies.


This skill is the study of magical theory and practice in a general sense. A good grounding in this knowledge is necessary for mastery of spell-casting. A character's effective skill level (i.e. after modifiers) in a spell can never be higher than one's level in Thaumatology, though the base skill level may be higher. Thus anyone who wants to be a competent wizard needs to invest substantial time learning the fundamentals of magic.

A character receives a bonus to final Thaumatology skill level equal to his level of Magical Aptitude.

Spell Prerequisites

Any spell can be learnt by any person, regardless of prerequisites listed in standard GURPS books. However, to avoid wizard characters learning only the most powerful spells, each "skipped" prerequisite exacts a cost of 1 on the final skill level of a spell.

For example: Fireball normally requires a chain of 3 spell prerequisites. A character of IQ 13 investing 4 character points in a non-magical M/H skill would have a skill of 13, but would only have a skill of 10 in Fireball. If this character later learnt Ignite Fire, one of the skipped prerequisites, to level 12, his skill in Fireball would immediately increase one point to 11.

Although not a prerequisite, anyone who wants to cast spells reliably should have some level of Thaumatology skill.

Casting Spells

Casting spells does not (usually) cost the spellcaster fatigue points. Rather, the cost of a spell is added to a running Tally. When this Tally reaches or passes a certain Threshold value, the nature of reality in the universe can be disrupted, usually in negative ways, and sometimes disastrously. The further above the Threshold the Tally rises, the worse the effects. Generally though, the spell will still work if the spell skill roll is made. Disasters are side effects of using too much magic in too short a time.

Casting a spell always requires a Will roll, the Magical Will roll. Magical Will is normal Will plus any Magical Aptitude bonus. The game procedure for casting a spell is as follows:

  1. Declare the spell to be attempted.
  2. Declare level of gesture and incantation to be used (see below).
  3. Declare any extra willpower to reduce spell cost (see below).
  4. Declare any special effort to reduce spell cost (see below).
  5. Make Magical Will roll, using bonuses/penalties determined in steps 2 and 3.
  6. If Magical Will roll succeeds, make spell skill roll to determine success of casting, applying bonuses/penalties determined in steps 2 and 4. If the Magical Will roll fails, the spell cannot be cast on this attempt, but the cost of the spell is not added to the Tally. If the Magical Will roll is a critical success, the spellcaster may take either a +3 bonus to the spell skill roll, or reduce the final cost of the spell by 1. If the Magical Will roll is a critical failure, the spell cannot be cast on this attempt, and the spell's cost is added to the Tally!
  7. If the spell skill roll succeeds, the spell works as intended, and its cost is added to the Tally. If the roll fails, the spell fails, and 1 point is added to the Tally regardless of the spell's cost. If the roll is a critical success, the spell works particularly well, but its cost is still added to the Tally. On a critical failure, the spell backfires, and its cost is added to the Tally.
In normal cases, steps 2, 3, and 4 can be skipped and the defaults assumed, which result in no modifiers to the rolls.

Modifying the Casting Process

Gestures and Incantations

Normally casting a spell requires speaking words of power and making physical gestures. This requirement does not reduce automatically with higher skill levels. A spellcaster may however use sheer willpower to attempt magic with reduced ritual components. Refer to the following table.

Normally a spellcaster will be assumed to be using the normal gesture and incantation levels, which result in no Magical Will modifiers. The player may however declare an attempt to use different levels of gesture and incantation to cast a spell. The gesture and incantation levels may be chosen independently. Add together the modifiers and apply them to the Magical Will roll. If the Magical Will roll succeeds, also apply the same modifiers to the spell skill roll.
Gesture Incantation Effect
Extravagant. Full arm and leg movement. Loud and clear. +1 bonus.
Normal. Full arm movement. Normal speaking voice. No bonus/penalty.
Subdued. Wrist/hand movement. Soft speaking voice. -1 penalty.
Tiny. A finger or two. A whispered word or two. -2 penalty.
No movement. No sound. -3 penalty.

Cost Reduction by Exerting Willpower

The spellcaster can exert his own willpower more forcefully in an attempt not to upset the delicate balance of magic and nature as much. He may expend Fatigue (and/or hit points in an emergency) in units of 3 to attempt to reduce the spell cost by 1 point for each 3 Fatigue/hits spent.

Normally a spellcaster will be assumed not to be expending Fatigue. If the player declares a Fatigue expenditure, the Fatigue is immediately spent. This gives a penalty to the Magical Will roll equal to a third of the Fatigue points spent, rounded up. However, if the Will roll is made, the spell cost is reduced by 1 for each three full Fatigue points expended.

Cost Reduction by Special Effort

The spellcaster can make a special effort not to upset the delicate balance of magic and nature by attempting to fit the spell into the local mana flow. The cost of a spell added to the Tally can be reduced by 1 point for every -3 penalty the caster takes to his effective spell skill, representing the difficulty of conforming the spell to the mana flow. This does not affect the Magical Will roll.

Spell Ranges

Instead of a spell skill penalty of -1 per hex for Regular spells, the penalty is determined from the Speed/Range Table. Add 2 to the range in hexes, so that touching counts as a "range" of 2 and has a zero penalty.

Example Spellcasting

Mad Harry knows the Sleep spell at level 20. His Thaumatology skill is 15, his Will is 13, and he has a Magical Aptitude of 3. He wishes to put an orcish guard across a castle courtyard to sleep, without drawing attention to himself. The orc is 8 hexes away. Adding 2 gives a "range" of 10, which is a -4 skill modifier on the Speed/Range Table. Harry is hidden from sight, but does not want to make much noise, so he whispers a couple of quiet words (-2 penalty) while gesturing extravagantly to try to make up for the lack of incantation (+1 bonus). He has also used a lot of magic recently and does not want to upset the local reality too much, so decides to exert extra willpower to keep the cost of the spell down. Harry expends 3 points of Fatigue for a -1 cost. He now makes his Magical Will roll, against 13 +3 (Magical Aptitude) -2 (whispering) +1 (extravagant gestures) -1 (extra willpower) = 14. He rolls a 7, so continues to the spell skill roll. This is against 20 -4 (range) -2 (whispering) +1 (extravagant gestures) = 15. Since this effective skill is not higher than his Thaumatology level, Harry rolls against the 15, scoring a 12. The orc unfortunately makes his resistance roll, rolling under his HT by more than 3 points. Sleep normally has a cost of 4, but because of the extra willpower Harry put into the spell, only 3 points are added to the Tally. Harry sighs, realising another spell could damage the local mana flow and seriously jeopardise his chances of escaping, and pulls out his sword.

Tally, Threshold, and Recovery

These are game mechanical numbers whose general behaviour is described below. The GM should set specific details for locations important to a game using these guidelines.

The Tally

The Tally is a running total of the magic points spent in an area in the recent past. Each point in space has a Tally value associated with it, and that value is increased whenever anyone casts a spell in the vicinity. A spell adds to the Tally in an area of variable radius around the casting point.

In general a spell adds its full cost to the Tally in an area about 100 hexes in radius, though this can vary between about 10-1000 hexes. The addition drops rapidly to zero outside this radius. [The 100 hex radius is more a narrative mechanic than a hard rule. It is meant to prevent wizards from casting multiple spells with impunity simply by the normal walking around done in an adventure episode, and can be modified by GM fiat for dramatic necessity.]

The actual area of effect depends on the structure of the local mana flow, and can be affected by physical reality. For example, a castle, or single set of catacombs, or city block, or large forest grove, forms a distinct physical structure of about the right size, so channels the mana flow around that particular region. A spell cast in a castle will likely (but not invariably) add to the Tally within the entire castle, but not outside it. The localisation of mana flow to physical structures means that mobile structures, such as ships at sea, carry a Tally with them, rather than drifting through open seas of zero Tally.

The Threshold

The Threshold is a value also related to location. As long as the local Tally remains below the Threshold, the mana flow is stable. If any magic use pushes a Tally above its Threshold value, the mana flow is disrupted and reality can be adversely affected.

Whenever magic use pushes the Tally above its Threshold, a Calamity Check is made. If the Tally is already above the Threshold, any use of magic, even one with no cost, triggers a Calamity Check. A Calamity Check is made by rolling 3d, and adding 1 for every full 5 points the Tally is above the Threshold. Look up the result on the Calamity Table.


The Tally in an area eventually drops of its own accord as the normal mana flow reasserts itself. It usually takes at least a full day before points added to the Tally are removed. The Recovery Rate is usually about 8 points per day, but may be spread unevenly throughout the day.

For example, an area aspected with death magic might recover 8 points at midnight, while an area aspected with life magic might recover 1 point per hour during daylight.

Sensing the Tally and Threshold

A character does not automatically know what the current Tally and Threshold in his location are. If he wants to know, he can take a turn to Concentrate, making a Thaumatology roll to sense the details of the mana flow. The GM should roll in secret.

A success will reveal a qualitative feeling for the current Tally and Threshold in his current location, along the lines of "a little magic has been used here recently, and 2 or 3 reasonably powerful spells could be cast before anything bad happens". A critical success will reveal whether the immediately intended spell will push the Tally beyond the Threshold or not. A failure reveals only how much magic has been used (Tally), but no Threshold information. A critical failure reveals incorrect information; the GM should lie.

GURPS is Copyright © by Steve Jackson Games Incorporated.

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