Sci-fi writer Larry Niven has written a couple of fantasy novels ("The Magic Goes Away"), ("The Magic Comes Back") which have as a central plot element, the idea that mana is obtained from one''s surrondings and that it can be depleted. I think that this could be used to make quite an interesting magic system. For simplicity''s sake, lets divide up the world into hexes and give each hex 10 mana points. Casting a spell first uses up mana on the wizard''s current hex, and then the surronding hexes if needed. A hex could regain lost mana at say one point a turn. To make things a bit interesting, let''s say that mana from the local hex can be channeled instantly while the surronding hexes take one turn per unit distance from the wizard. So, a spell requiring 10 mana or less could be cast in a single turn. The six hexes surronding the wizard''s hex can provide up to 60 more mana making spells requiring 11-70 mana two turns to cast. The further out the mana has to come from, the longer the spell takes to cast. In addition, a wizard of a particular level may have a restriction on the distance he can channel mana from. If you have multiple wizards casting, you can create some complex tactical situations. For instance, if a wizard is casting a complex spell, you could run up close to him and start casting simple spells to drain nearby mana, thus lengthing the time needed for his spell to be cast. This gives you more time to continue your draining spells. You could apply this system to a 3D world and have mulitple "colours" of mana. Then use vertex coloring to indicate the colour and strength of mana in a particular location. I think that magic systems can be so much more than a single integer representing magic points.

That''s a pretty nice system.

I''m going to post my magic expenditure system for Pentaverse, just to offer another non-single-number-based system. (This is not the old DMS, so don''t dismiss it out of hand!)

Spells range from levels 1-10. Spells of level x cost 2X + or - 1 MP.

In addition, you must have access to the appropriate magical alignment to cast spells. All spells belong to one of five complex schools, each of which is more like a color of magic than a D&D school of spellcasting. When you cast a spell, 4(X^2) alignment points are drained from that spell''s alignment factor and one-fourth that number are added to each other school''s alignment factor. You must have a high enough alignment factor in a school to cast a spell, so alignment factors cannot become negative numnbers.

In addition, if you are within 30 feet of enemy spellcasters, their alignment factors begin to merge with yours temporarily. The closer you are, the more your alignment factors effect theirs. In addition, time of day, day of week, and location can influence your alignment factor slightly.

To sum up the system, you must spend time casting weak spells of a school before you can cast stronger spells of another school. Once you cast a particularly strong spell, the energy from that spell is scattered among your other schools, giving you enough energy to perform moderately powerful spells in other schools, but leaving the energy for the school from which that spell was cast badly drained.

Sorry if this is a bit incoherent. My left brain doesn''t function very well after 6:00. I can explain everything in the morning if anyone doesn''t get it.

BTW, Factors now start at 40 total, divided among all five schools equally when the game starts and increase by 10 each class level.

"Ph''nglui mglw''nafh Cthulhu R''lyeh wgah''nagl fhtagn!" - mad cultist, in passing

As I recall, Larry Niven wrote quite a number of short stories and novels set in what I think of as his "Atlantean" universe - all of which had as common assumptions that magic used to be plentiful, but that, according to the 2nd law of thermodynamics, it inevitably declines over time - further that mana can be drained more rapidly by deliberate usage, producing dead zones where ordinary background magic of various animals, etc fails (at least until they enter an area with mana again)

Atlantis was kept intact by a relatively major complex of spells. Most of the stories I''ve encountered in this universe are set around the time (within 100 years or so either way) that the spells sustaining Atlantis failed. I haven''t read either of the novels cited, but they sound like the same system. One quote that keeps popping up from time to time is "water cannot run down-hill forever", which pretty much summarises his attitude towards magic.

Margaret Ball''s "Lost In Translation" has a vaguely similar system - there "landvirtue" is produced by the earth and used by plants in growth. "Landsensers" have the inborn ability to sense, absorb, control and redirect accumulations of this energy, which if allowed to accumulate will tend to axpend itself in the form of "landmonsters" - initially plant-like creatures that develop into more mobile forms, ultimately becoming something resembling an elemental. The form of a landmonster is heavily influenced by the cause of the excess landenergy (usually destruction or damage of vegetation, can also be produced by spilling of life-blood on the land - violent death tends to produce a reactive surge of landenergy). Adapting this concept could provide the basic scenario for an FF style game very easily - destructive monsters rise up out of the earth to attack passers-by in random encounter style all along the wake of the story villain (probably gifted with landsense) who wakes the land for whatever reason (possibly to extend lifespan). The hero(ine)(s) is the only person with landsense enough to stop the villain... The plot practically writes itself...

The Dark Sword trilogy by Margaret Weis and Tracy Hickman had something similar to this. Every one could cast/use magic and every thing surrounding them had magic infused with it in some degree.

It''s been a while since I read the books but it went something like this.

Each person had a small pool of their own magic that they could store in themselves. This would naturally restore/replenish as they rested, ate, etc. The magic from the surroundings would seep into them.

If they needed a charge they had to get someone known as a Catalyst who could directly open a channel to objects around him/her, then open a channel to the person needing the magic and channel that power from the object to the person. The side affect of being able to channel all this power to another person was that a Catalyst had a VERY low personal pool of magic for his own use so by themselves they were very weak.

The standard magic fight would be a warlock and a Catalyst against another warlock and Catalyst team. The usual tactic was to take out the opposing Catalyst so the opposing warlock would run out of magic. So of course warlocks would defend their Catalysts.

Another interesting twist was that the Catalysts could try to open a channel to the opposing warlock/Catalyst and steal their magic and increase his warlocks power. This had its own problems because the targeted warlock could cause a surge of too much magic along the line causing damage the Catalyst trying to steal the power.

I thought there was a comercial MMORPG that used depletable mana system. Oh, wait I''m probably wrong, it was something like the more a spell is used the weaker it was so players should (in theory) be forced to diversify their casting. Was it Asheron''s Call? Okay not exactly like your system but similar in some ways.

You''re right, it was Asheron''s call. I''ve heard that their magic system''s been changed, but I don''t know too much about that as I''ve never played the game.