The Demesnes - Variant GURPS Rules

Hit Points and Fatigue

Instead of being equal to HT, Hit Points are equal to ST. Instead of being equal to ST, Fatigue is equal to HT.


Instead of being equal to IQ, Will is split into three components: All of these are modified by Strong or Weak Will.

Wizardly Magic

Magical Aptitude

Magical Aptitude can be learnt, and thus bought with character points during play. It costs a flat 10 points per level, not 15 at the first level. Each level (up to 3) gives a +1 bonus to all spell skills and Thaumatology skill.


When casting magic, a wizard's effective spell skill (after modifiers) may never be greater than Thaumatology skill. Note Thaumatology defaults to IQ-6 for characters who do not know it, so such characters will be at a severe disadvantage if they attempt magic. Thaumatology skill is also used when a wizard wishes to sense whether casting a spell is likely to cause a magical disaster.

Spell Prerequisites

Spell prerequisites consisting of other spell skills are not required. Magical Aptitude prerequisites remain. A wizard's final skill level in a spell is modified by -1 per missing prerequisite spell (including all spells in the shortest prerequisite chain).

Spell Ranges

Instead of a skill penalty of -1 per hex of range for Regular spells, apply the penalty from the Speed/Range Table, with touch equalling 0 penalty.

Spell Costs

Spell costs are simply a measure of how much mana must be drawn to power the spell. Spell costs do not reduce with high skill levels. Spell costs are not deducted from the wizard's Fatigue.

However, if a wizard wishes to reduce the risk of a Magical Disaster, he may elect to spend Fatigue (and/or Hit Points in an emergency) to use mana from his body to partially or fully power the spell. Each Fatigue or Hit Point spent supplies one mana point to the spell, but also gives a -1 penalty on the Mental Will roll. A Mental Will roll is still required to gather the mana in a usable form, even if the full cost of the spell is supplied from the caster's body. However, if the full cost comes from the caster's body, there is no chance of a Magical Disaster.

Another method of reducing the risk of Magical Disaster is simply to attempt the spell using less mana than normally required. For each 1 less mana available to power the spell, a -3 penalty on the spell skill roll is assessed. A spell must always use at least 1 mana though - this can never be reduced to zero.

Spell Casting Times

Spell casting times do not reduce with high skill levels.

Gestures and Incantations

Gesture Incantation Effect
Extravagant. Full arm and leg
movement. Takes twice as long.
Loud and clear.
Takes twice as long.
+1 Will if both.
+1 skill each.
Normal. Full arm movement. Normal speaking voice. No bonus/penalty.
Subdued. Wrist/hand movement. Soft speaking voice. -1 Will, -2 skill.
Tiny. A finger or two. Whispered word or two. -2 Will, -4 skill.
No movement. No sound. -3 Will, -6 skill.
Normally casting a spell requires speaking words of power and making physical gestures. This requirement does not reduce with high skill levels. A spellcaster may however use sheer willpower to attempt magic with reduced ritual components, or enhance the ritual to improve chances of success. Refer to the table. The gesture and incantation levels may be chosen independently. Add together the Will modifiers and apply them to the Mental Will roll. If the Mental Will roll succeeds, apply the skill modifiers to the spell skill roll.

Casting Spells

Spellcasting is a two-step process. After the required concentration time:
  1. Roll against Mental Will, with appropriate modifiers and a bonus equal to Magical Aptitude level, to gather the required mana for the desired spell:
  2. If the Mental Will roll was successful, roll against spell skill with appropriate modifiers:

Magical Disasters

If the amount of mana gathered from the environment for a spell causes mana to be drawn from a great distance, a Magical Disaster may occur. This may range from a small noise and light show, to summoning a demon, to devastating large tracts of countryside, depending on the size of the area required to supply the needed mana. Exact effects are unpredictable. Very powerful spells are very dangerous.

Prior to gathering mana for a spell, a spellcaster may Concentrate for a second and roll against Thaumatology to determine if a Disaster is likely. The GM rolls and on a success informs the player in qualitative terms what the chances are. There may not be time for this in a combat situation though!

Maintaining Spells

If a spell is to be maintained, another Mental Will roll will be required to gather the appropriate mana for the maintenance cost. This may end up causing a Magical Disaster. Fatigue or Hit points may be spent to supply the mana, as with casting the spell. If the full maintenance cost is available, another spell skill roll is not required. If the full maintenance cost is not available, another spell skill roll will be required, at a -3 penalty per missing point of mana. Unlike casting, a maintenance cost may be reduced to zero - this will not require a Mental Will roll to gather mana, but will require a spell skill roll at the appropriate penalty.

Distraction and Injury

If a spellcaster is distracted while concentrating on a spell, the Mental Will roll is made at a -3 penalty. If the spellcaster is injured while concentrating, make an immediate Physical Will roll to maintain concentration. If this roll fails, the mana being gathered is lost, dissipating harmlessly. On a Critical Failure the mana is released catastrophically. Even if the Physical Will roll succeeds, the spellcaster has a penalty on spell skill equal to the number of Hit Points of damage taken. A Critical Success eliminates this penalty.

Improvised Magic

A spellcaster may attempt any spell he has not specifically studied, or even any magical effect that he can think of, by using an improvisational technique.

If a spellcaster wishes to produce an effect that duplicates a spell described in GURPS, he may cast that spell at a default level equal to Thaumatology-6 (or Thaumatology-8 for a M/VH spell). This default skill level is reduced as described above if the caster does not know some of the normal prerequisite spells. In addition, there is a -3 penalty to the Mental Will roll for an improvised spell, -6 for a M/VH one! If the desired spell requires a level of Magical Aptitude greater than the spellcaster possesses, he cannot successfully improvise that spell (but the GM should let the player try and fudge the results to produce failure).

If a spellcaster wishes to improvise a magical effect which does not duplicate an existing spell, the GM must rule on spell difficulty, cost, and any suitable prerequsites, then proceed as above.

Clerical Magic

Power Investiture

This advantage is required for casting clerical magic. Each level (up to 3) gives a +1 bonus to all clerical spell skills.


This skill is required for casting clerical magic. When casting magic, a cleric's effective spell skill (after modifiers) may never be greater than Theology skill. Theology skill is used when a cleric wishes to sense whether casting a spell is likely to cause a Magical Disaster. Theology is also the relevant skill when a cleric prays for spells not normally granted by his deity. It is also used when a cleric wishes to Concentrate (pray briefly) to learn how likely a Magical Disaster is.

Clerical Spells

Clerics may normally only cast spells approved for use by their deity. Casting such spells follows the procedure for casting wizardly spells, except that the Mental Will roll receives a bonus equal to the level of Power Investiture.

If a cleric needs access to a spell or magical effect not normally granted by his deity, he may pray for it. Use the rules for improvised wizardly magic, replacing Thaumatology with Theology, and also granting bonuses or penalties for appropriateness of the spell in terms of the god's goals and moral strictures.

Magical Items

Recharging Stored Mana Items

Items which store mana and are capable of being recharged (usually wands and staves) are recharged using the Imbue Mana spell. This allows an immediately following spell to be cast into the item, storing the mana of that spell.
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