Though it might require channeling a bit of negative e into this thread, I though I'd share a "magic system" that might be worthwhile for game designers to consider.
Namely, the "magic" system from Brandon Sanderson's Mistborn series. There are three actual systems of "magic": allomancy, feruchemy, and hemalurgy. Sound scientific-y? Good, because Sanderson's "magic" is rather so. As the names imply, magic is based around metals.
For Allomancy, one ingests a metal such as iron and then "burns" it to produce an effect. There are a variety of base metals and a related alloy that have specific and inverse effects. For example, if someone burns iron, they pull metal directly towards them (thus either moving themselves or the metal itself, depending on weight). In contrast, if they burn steel, they push metal directly away (again, moving either themselves or the metal, depending on weight and the like). In the series, someone who can burn steel is called a "coinshot" from the obvious application (burn steel to essentially use coins as bullets sans a gun). Another pair of metals is tin and pewter, the former of which increases senses (such as seeing farther, hearing better) and the latter of which increase physical abilities (stronger, faster, harder to hurt, quicker to heal). There are other pairs, but I think you get the basic idea.
For feruchemy, the same metals and alloys are used, but instead of burning them to get an effect, attributes are stored in them for later use. One could store strength now in order to draw upon it later. Basic energy over time applies. One could be half as strong for an hour to be 1.5 times as strong for an hour later, or twice as strong for half an hour, etc. Different metals allow one to store different things, such as vision (poor eyesight now, better eyesight later), speed, healing, memories, and other things. Unlike Allomancy, which has a natural limit (one can only become so strong burning pewter), there is no essential limit to feruchemy: one could go years storing weight in metal, and then pull it all out in just a few seconds in order to become heavy enough to collapse a tower. The limitation is, though, that only the person who stores the attribute can get it back out.
Which brings us to hemalurgy (spoiler alert). Simply put, stab a spike of a certain metal through one person and into another person, both in a certain location, in order to transfer "power" from the first individual to the second (at a loss). Not an allomancer? Stab an allomancer with the right spike in the right spot and stick that spike into yourself, and you will take their power. This can change the physiology of a creature (it applies for animals as well as people), and it can drive a person nutters, but its potent stuff.
They just released a game based off the series, so if these systems look interesting, you might want to check it out for inspiration: http://rpg.drivethrustuff.com/product_i ... s_id=95856
Just a thought