By S. John Ross

Revised with "Yed house rules" August, 1998*

Reprinted from Pyramid magazine #9 (Steve Jackson Games). GURPS is a registered trademark, and Pyramid is a trademark, of Steve Jackson Games, Inc.

IF you've found this page, you are either part of my online GURPS game, or you've somehow blundered in here by accident. As this material is only for the players of my game, and not for the public, if you've gotten here by accident, please leave now.

* This is a revision of the original UMana rules, as used on the game world of Yed. Some parts have been added, while others have been changed or deleted for clarity when used on Yed. The original document can be found here. Changes and additions are done in GREEN

Standard GURPS magic is "tactical;" mages can create dozens of small effects in a given day -- but very few (if any) world-shattering miracles. Manipulations of mana, the force behind spells, leaves sorcerers drained and weak. Thus, GURPS wizards are limited by their knowledge (which determines their flexibility) and their physical stamina. "Powerful" wizards are wizards that know more spells at higher levels than others.

Absent from this basic structure is the concept of Raw Power - wizards that can crack a castle in half or drown an army in flames.

Fantasy novels that feature such levels of power rarely have mages that get ``tired out'' by magic. Instead, extreme effects threaten the fabric of the universe, creating a situation in which wizards can create true miracles in times of need, but do not use their powers frivolously. When their companions ask for more magic, they will drone cryptically "To draw too deeply on my Gift can lead to madness and death. Do not demand of me what you do not comprehend."

Fantasy writers need character balance as much as GMs do. While it's exiting to establish that a sorcerer can wreak serious havoc when needed, it's boring to let him overshadow the rest of the characters. That cryptic double talk exists as a handy plot device, no less than the wizard himself.

This approach to magic has been left untouched in gaming, and for good reason. It's easy for a writer to create a wizard that will be prudent with his arcane wisdom. Trying to get an ambitious fantasy gamer (even a well-meaning one) to do the same is risky at best. GURPS has no such bounds, however. The magic system is flexible enough to permit Unlimited Mana that will balance in ANY fantasy campaign, even the lowest of "low fantasy!"

The Power Tally

"Unlimited" isn't a mana level, it's a mana TYPE. In an Unlimited Mana (Umana) campaign, spells do not cause fatigue.

When a mage casts a spell, he should record the cost in a running tally, instead of taking the cost from his ST score. All normal rules for costs (skill reduction, etc.) remain in force.

Example: Magus Wiltshire finds himself caught in a besieged city. He has not used magic in a while, and feels that the present emergency justifies it. In his attempts to escape unnoticed, he casts a huge (cost 16) Mass Sleep spell on a group of guards. Three guards are unaffected, and Wiltshire, furious, casts an Entombment spell on one of them, which increases his tally by 10 points to 26. Two guards remain . . .

Threshold and Calamities

Every mage has a Threshold (THRESH) score -- this defines the safe limits of his magic. If his tally remains at or below his Thresh, everything is fine. If his tally exceeds his Thresh, Bad Things can happen, and the mage must roll on the Calamity Table. The "default" Thresh score is is based upon magery level. Magery 1 = Thresh of 15. Magery 2 = Thresh of 25. Magery 3 = Thresh of 35. An untrained potential mage has NO Thresh score at all! (See section below on "mage potential").

"Calamity Checks" are made by rolling 3d, and adding 1 for every full five points by which Thresh has been exceeded. The spell that first brings the mage's tally over Thresh triggers a check. After that, ANY spell cast by the mage (even those that cost no energy), will also trigger new Calamity Checks at the current level of excess. Calamities take effect immediately, but their nature may not always be apparent to the mage (see the table for details). Calamities do not normally cause the spell to fail (but see results 29+).

Example, Part II: Magus Wiltshire, a Magery-2 mage (Thresh 25) mage, exceeded his Thresh when he cast the entombment spell. This requires a calamity check. Since Wiltshire exceeded his Thresh only by 1, there is no modifier to the roll. If he decides to entomb the other two guards, each new casting will trigger a fresh calamity check, and modifiers will begin to apply.

The Recovery Rate

The mage's Tally is healed by an amount equal to his Recovery Rate (RR). The "default" RR score per day is 8, with a point of recovery occurring every three hours, in a normal mana area. In a high mana area, RR is doubled, but in a low mana area, the RR is halved.

Mana Level

The mana level of an area effects the mage's threshold. In a low mana area, subtract 5 from the mage's threshold. However, in a low-mana area, if threshold is exceeded, also apply a -5 to rolls on the calamity table. No modifiers in a normal mana area. Add 5 to threshold and calamity checks for high, or 10 to both areas for Very High mana areas.


The numbers above create an overall power level equivalent to the current rules. Mages can't cast nearly as many smaller spells, but they can (in emergencies) cast some very LARGE spells. Area spells, in particular, become more of an option in combat, and more "strategic" levels of magic become possible.

These basic numbers, however, are open to change. Thresh and RR defaults are a campaign decision for the GM. A Thresh of 50 and a RR of 1 per day would allow mages to cast REALLY powerful spells safely, but would cripple them on a day-to-day basis. A Thresh and RR of 40 each would make for a world where mages are godlings that walk the soil - Unusual Background would be appropriate to keep them balanced! At the other extreme, Thresh and RR of 5 each would create a distinctly low-magic world, where mages could still use relatively mighty magic in times of dire need, and at great personal risk.

The third assumption -- that Recovery occurs daily at sunrise, is also variable. Even with a standard daily rate, wizards might have their own ``hour of recovery'' chosen at play. Alternately, a campaign might feature recovery every hour, or every week, or every (gasp!) month. The latter would lead to a dramatic thinning-out of magical activity just before "payday," but some GMs might like that idea~!

New Advantages, Further Ramifications

Mage Potential

5 Points/1st Level, 2 points/2nd & 3rd level

This advantage may be taken by any new character. The effect of "mage potential", is to allow the character to buy magery later (at the normal cost), and thus lower the initial character cost for a (potential) mage. A character with "Mage potential" may cast spells, but with the following restrictions:

Only using their own fatigue or health. (no Threshold to draw on, and see rules on strength & health use below.)

The apprentice mage may only learn and cast spells that don't have magery as a prerequisite.

The apprentice mage may only know a maximum of 5 spells, which may be spread over no more than 3 colleges until magery is purchased. The potential mage must buy (at least) magery 1 to advance further. (Their Gift has to be awakened).

Magery may only be bought up to a level equal to Mage Potential level(s). For example, the dread apprentice Fritz has Mage Potential-2. He may later spend character points to buy Magery 1 & 2, but not Magery level 3. He may buy the Magery levels one at a time, or together, at the players choice. The player could still, of course, buy Magery outright, avoiding this extra cost. The character could also buy some magery, and then pay the cost for more future "potential".

The apprentice mage may still use scrolls and such that could be used by any "ungifted" character, but not any that require magery (until it is bought).

Increased Power

10 Points/Level

This advantage may only be taken by mages. For each level of Increased Power that you have, increase your Thresh by 20%, and your RR by 25%, of the campaign average (round normally).

Each of these effects can also be purchased individually for 5 points/level, as the Increased Thresh and Rapid Recovery advantages. Mages may not purchase decreased levels of Thresh and RR; the campaign default defines the weakest levels of personal power.

Safer Excess

10 Points/Level (Limit 4 Levels)

This advantage may only be taken by mages. Your calamity rolls are at +1 for every 10 points of excess, instead of +1 per 5. Every additional level doubles this effect (+1 per 20, +1 per 40, +1 per 80).

With unlimited mana, mages can now be defined in terms of both versatility and raw power -- a 250-point mage might have a vast grimoire, or a limited, predictable repertoire and earth-cracking mana-resources! This gives players and GMs more freedom, and has many small side-effects that need the GMs consideration. Powerstones, for instance, become less desirable for many wizards, and some spells formerly limited to Ceremonial Casting can be cast by individual wizards! GMs fond of adding new spells to the campaign can add VERY powerful ones, balancing them with costs as high as they see fit, and even Thresh or RR-based prerequisites.

Optional Expansions

That's all there is to the basic Unlimited Mana option, but this basic framework can be built on to make all sorts of dramatically different uses of the GURPS magic rules. Consider any of the following:

Spending Options

Mages may spend energy to make their spells faster (4 points per second of reduction, which will even affect missile spells and bring spells to ``zero time'' if sufficient energy is spent). They may also increase their odds (1 point of energy per +1, or 3 per +1 if the spell is to be resisted). At the GMs option, even the odds of hitting with a Missile spell can be increased on a +1 per point basis!

This option actually works very nicely in play, allowing much greater flexibility for mages at appropriately high energy costs. Players tend to overspend at times, but the rules keep such mages nicely in line . . .

Option to Spend Fatigue

Mages may take fatigue or health to help power their spells, but it costs 3 fatigue or health to produce 1 point of spell energy. Thus, mages won't bother with using their ST for most castings, but in an emergency they can exhaust themselves for an extra point or two of power.

Partial Fatigue

Every spell cast causes 1 fatigue, in addition to the increase of the mage's tally. This limits the NUMBER of spells a mage can cast in a given scene, without limiting their power.

Recovery Rituals

The daily recovery needn't be automatic. Perhaps the mage must burn incense and meditate. Likewise, there might be some rituals that will trigger additional levels of recovery beyond the daily standard. This will be a case by case basis, as part of the character concept.


Special thanks to Scott Maykrantz, Bill Collins, and the other contributors to All of the Above for their comments on earlier versions of this article. Very special thanks goes to my local gaming group, the Lower Reprieve Generals' Club, for play testing this with me for the past three years.

This revised version is dedicated to Marty Franklin, who played Cormidigar, the first Umana mage to explode in play. Every campaign needs a Marty. We have a really big, blonde one.



Nothing bad happens, AND the mage gets (1d x 5) points of free, instant Recovery!


Nothing happens - this time.


The mage's skin and clothing crawl with strange energies, sparks, or other visual effect for 3d minutes, and his eyes glow bright, making Stealth impossible and frightening small animals and many "mundanes."


The mage is struck with violent headaches that prevent any action other than suffering (treat as physical stun) which lasts 3d turns (3d minutes if a HT roll is failed). Result 10 also applies.


The mage becomes horribly nauseous and weak, taking a -4 to DX, IQ, ST and skills. This lasts 1d hours, after which the mage must make a HT-4 roll every hour to get over the sickness.


The mage is cursed with nightmares for 4d days. After the first night, the mage is at -2 to DX, IQ, ST, and skills. The penalties last until the mage gets a normal night's sleep!


Any failed casting roll that the mage makes is treated as a critical failure! This lasts for 1d+1 weeks.


The mage's mind is bent. The GM should assign one debilitating (15-point) mental disad by fiat. It takes effect immediately, and lasts 1 day. Each day thereafter, the mage may make a Will roll to shake it off.


The mage has weakened the binding forces around him. His Threshold for the next 1d weeks is reduced by 2d+5. The mage is aware of a drop, but not of it's severity! Result 10 also applies.


The caster gains a 5-point disadvantage. After 3d days have passed, the mage has the option of buying it off (it will simply fade away). If the mage does not wish to, or doesn't have the points, then it becomes permanent. ANY disad is legal; the mage can get ugly, go insane, and so on.


The mage's Threshold is reduced by 4d+10; the change lasts 1d months! In addition, the mage's spell casting will be at a -3 penalty for 2d weeks. Result 10 also applies.


As per 17, but the disad is worth either 10 or 15 points (50/50 chance of either).


The mage is aged 2d+13 years, or a number of years equal to the energy cost of the spell that caused the calamity, whichever is worse!


Roll again (same modifier) but the result affects a companion of the mage (chosen randomly).


The mage gains multiple disads worth a total of (2dx5) points. These are permanent.


The mage loses permanently the ability to cast a single spell. The skill is still known, but it cannot be cast. The mage must make a (Will-6) roll. If it is successful, he chooses which spell "dies." If not, the spell is chosen at random. On a critical failure, the GM chooses the mage's most useful or favorite spell!


The mage loses 1d x 5 points of advantages (or has an attribute lowered). Choose randomly.


The mage becomes a wandering Mana-Scar! Spells cost double within a 10-mile radius of the mage, and Recovery is HALTED in the same area! Every mage in the region will be gunning for him . . . The duration, in days, equals the cost of the errant spell, plus one. Result 10 applies for the ENTIRE duration.


The mage's skill at spells is reduced by 3d+5. The mage must make a Will roll. If it is successful, the penalty will heal at a rate of one per day. If not, the healing rate is one per week!


A plague or curse (locusts, storms, etc.) descends on the region, lasting for 3d+ weeks. No one will be able to trace this to the mage (-20 to divination attempts on the subject), but the mage will know the fault is his . . . Be grotesque and CRUEL.


The spell propagates out of control. Harmful Regular or Area spells will affect everybody and every thing nearby, allies and enemies alike. Beneficial spells will do likewise, but will go "over the top" and cause dangerous side-effects (a healing spell might raise all the local dead, creating a horde of restless zombies out for revenge!) Information magic will overload the mage's mind (Fright Check at -20); Missile Spells will seem normal to the caster, but have so much punch that they drill through their target and through EVERYTHING ELSE FOR MILES beyond, and so on.


The mage permanently loses the ability to cast spells, (but not the skills - small comfort). At this level and above, the spell that causes the roll fails unless a Will roll is made by the mage. The roll is at a penalty equal to the current "excess bonus" (Excess/5 for most mages), and at a bonus equal to triple the mage's level of Aptitude.


As per 29, and something happens to the region the mage is in. If the result on this table was an even number, magic itself is changed (the region becomes aspected, certain spells function erratically, or some such). If the result was odd, the change is to the physical world - the weather, birth rate, crops, or something else. Sometimes the result is good, sometimes bad (50/50). The duration is equal to the cost of the spell, in days.


As per 30-39, but a GLOBAL change occurs. In addition, the mage must make a HT roll at -6. If this roll is failed, the mage is consumed in a backlash of magical energy, and explodes. The explosion does concussion/burning damage like a grenade doing the mage's (Will+Magery) dice of damage! If the HT-6 roll is made, the backlash is less dramatic; the wizard takes 2d DICE of internal burning damage, and doesn't explode.

Heal Calamities (M/VH)


This spell is used to erase any ``regional'' or global change brought about by magical Calamity. It requires at least three mages and Ceremonial Magic (even if one mage has sufficient Threshold and Recovery to cast the spell, it cannot be cast by fewer than three mages). The mages must work together at least 8 hours per day during the casting, and may only rest and eat with the remaining time; they may not even study.

Casting Time: Equal to the die-roll that caused the calamity, times 2 hours. Thus, a roll of 35 would require casting of nearly 3 days! The casting circle must remain awake; alternate mages can take over ``shifts'' if need be, but at least 3 mages must remain in the circle at all times.

Cost: Equal to 1/10 the die-roll that caused the calamity (round up), EVERY HOUR OF THE CASTING. This may be divided among the casting mages in any way they can agree upon.

Prerequisites: IQ 15+, Dispel Magic, and a RR of at least 12.

This is a meta-spell.

EXAMPLE: Mordecai the Necromancer blew himself up trying to turn a dead Leviathan into a Zombie, and his calamity roll was 54, resulting in global ceasing of all rainfall that will last for months! To restore normal weather, a group of mages must work this spell for 4.5 days, spending a total of 6 energy every HOUR. This will require a LOT of powerful mages, all of whom must know this spell at a level sufficient to share the cost . . . When the world is at stake; things aren't cheap. After the casting is complete, the mages will likely want to summon up Mordecai's spirit from the afterlife, and beat the sh** out of it. Fair is fair.