Well, one magic system I like is the one used in the CRPGs Natuk and Nahlakh ( http://www.proudft.com for SW versions). In those systems, every attempt to cast a spell takes strength and makes spellcasting more difficult, until in the end of a long battle the wizards/clerics are usually only capable of casting very simple spells. Failing in casting usually took even more strength (and once the strength was gone, it would start draining HPs). In those games, magic was also fairly weak compared to, say, FFs or AD&D games (at least, the gold box games - I haven''t played BG) and was meant more to support the fighters and weaken the enemy before contact. IMO it''s far better than mana-based systems.

Personally, I prefer Betrayel at Krondor. Every spell you take drains your HP. Of course, this would take away the spell Heal, but sometimes you just have to compromise.

I like the systems where magic is used the other spells go down..like you have to exercise those.
so you have to keep using real attacks not just magic
real attacks to keep yoru hp up...
and spells you have to exercise too.
of course most people would probably only do magic..and little hp..but make hp need to be exercised more.
sound good?

I have been thinking this a little recently. Personally, I have been working to create a spell system that really encourages strategy and discovery. I think part of the problem with modern *fantasy* magic systems (disclaimer: there are bound to be exceptions, but this is in general) is that they lack a sense of mystery concerning magic. The sense of awe and mystery has left because magic systems explain and/or quantify everything (which is what computers are good at). In ancient times magic was a very strange and mysterious force that was to be feared and wasn''t completely understandable even to the magician!

I am considering using a system where there is a magical language that has to be put together piece by piece in order to create a spell. This way the player is not limited to a certain number of spells. The players could experiment with combining the pieces to create new spells and slowly discover the mysterious language of magic. Part of the effect of having a combination spell system is that a player needs time to cast a spell and also needs a clear head to remember how to create the spell (just like a real mage).

This system then, of course leaves the question of how do you control the level and complexity of spells being cast? One way is to assign a cost to each piece (or use some other formula to calculate the cost of a spell) and somehow subtract that cost from what a user is currently able to spend to cast a spell. The resource spent could be manna or health or strength or gold, etc. Another way is for a player to be required to have a necessary rune (or other item) to cast a piece of the spell. This way you can control how powerful of spell pieces that the player has by what runes they have. An idea I am still toying around with is to allow the players to cast any spell they want or know or, but they have a spell handling skill that determines the successfulness of casting spells. More complex spells cost more manna and have a tendency to backfire with creative results (not just the standard “The spell backfired and fizzled out or hit you instead” but rather “you just alerted all orcs within a square mile to your presence”, etc.). Of course there’s always the negative consequence of casting a spell, such as magic causes the mage to go crazy, blind, or even magic is an evil force that draws the attention of evil (think of the one ring from Tolkien).

Hope this helps give you some more ideas. I suggest going to a store that sells table-top RPG’s and thumbing through a few books to see how they handle magic, they sometimes can give good inspiration.

Hmm.. how about sacrifices? Like reagents, only they could be a bit more bulky and rare (or common).

For example, food, animals, or (!) people.

THAT would be interesting.