In the spirit of building upon the core foundation of the Fluidity Project, I’ve come up with a rough outline for another magic system. The system is based (loosely) on the magic in Steven Erikson’s Malazan Book of the Fallen series, where mages are merely conduits for vast magical power and don’t actually hold any power in themselves. Tentatively called Threshold Magic, the system is designed to be used with magical schools or paths which contain spells and either spell based augmentation (like Psionics) or universal augmentation (or both). Threshold Magic also makes use of a Channeling skill much like Elementalism.

A caster using Threshold Magic can channel magic as a move action. Casting a spell using the channeled mana is a standard action. In a more complete writeup, I would include a slew of feats, the least of which would lower the time for both casting and channeling.

A mage channels a static amount of mana based on the result of thier channeling check — say, 1 mana for every 5 points of the channeling check above 5 (1 mana for 6-10,2 mana for 11-15, 3 mana for 16-20, etc.)

Mages have a mana threshold that simulates the toll that channeling mana takes on a mage’s body. The threshold has an upper bound (twice a mage’s hit dice for argument’s sake) and a lower bound (a mage’s constitution modifier).  This ultimately means that a mage with low hit dice and a high constitution will never take non-lethal damage. I’m not sure right now if that’s a feature or a bug.

When a mage casts a spell, he rolls a channeling check to see how much mana he can pull from the “source” (be it warrens or whatever the mage gets his power from). A mage can always choose to channel less mana than his roll indicates. Likewise, a mage also doesn’t need to spend all the channeled mana on one spell.

When casting a spell, if a mage spends less mana than his lower bound, he takes no damage. If a mage spends more mana than his lower bound, but less mana than his upper bound, he takes non-lethal damage. If a mage spends more mana than his upper bound, he takes lethal damage.

Every time a mage spends mana, that amount spent is subtracted from the mage’s upper and lower bound.

A mage’s lower bound regenerates at a rate of 1 point per hour and the upper bound regenerates at a rate of HD+Con per day (after 8 hours of rest).

Each mana spent deals two (or whatever, 2 is just a shot in the dark) points of damage to the caster. Non-lethal damage and lethal damage dealt by spending mana (we could call it mana burn) heals at the normal rate.

If a mage holds mana in his pool and does not spend it, that number isn’t subtracted from his upper or lower bounds, but it does give him a -1 penalty on all d20 rolls for as long as he holds mana within himself. A mage can choose to release any mana he holds at any time for no action.

A quick example to illustrate what I’m thinking here:

An 8 hit dice character with a Constitution of 16, Wisdom of 18, 10 levels of skills and skilled level of channeling has 76 hit points, a Mana Threshold of 3/16 and a Channeling check of +14. When this character attempts to channel, he pulls mana at a rate of 2 to 6.

During combat, the mage rolls an 14 (total of 28) and channels 5 mana. He now has a -5 on all d20 rolls. He decides to cast a 1 mana spell augmented with 2 mana. He takes no damage. His Threshold is now 0/13. He hold 2 mana in check for a -2 on all rolls.

The next round he decides to channel again he rolls a 10 (for a total of 22… rememeber his -2) and channels 4 mana, he now holds 6 mana (-6 on all rolls). He casts a 3 mana spell augmented with 3 mana. He takes 12 non-lethal damage and can handle 64 more. His threshold is now 0/7. He holds 0 mana in check.

The next round he channels again, rolling a 20 (total of 34) for 6 mana. He casts an unaugmented 6 mana spell hoping to end the fight. He takes another 12 non-lethal damage and can handle 52 more. His threshold is now at 0/1. He holds 0 mana in check.

Several rounds later, he needs to cast another spell. He channels again, rolling an 8 (total of 22), channeling 4 mana. He casts an unaugmented 4 mana spell, taking 8 lethal damage in the process, effectively leaving him with 44. His threshold drops to 0/0 and he ends the fight with no mana in check.

At this point, this is little more than a thought experiment.  I’m a little concerned about the amount of bookkeeping the constantly changing thresholds require, and a whole new pile of spells is a little daunting, but I think with a little work, Threshold Magic could work.