I just downloaded the Lost Empires beta and I’m finding myself enamored of its magic system. It’s a spell-point system at its core, but to my mind one done right – it looks like it’s almost painless in play, with very simple tracking.
All mages have a mana point pool. Various spells are rated in terms of dice they take from your mana pool, rather like Life Force in Pendragon 4e. A weak spell may be rated d4, while really powerful ones may be d20. There are no level limits for what you can cast; if you want to risk casting a d20 spell at first level, go ahead! The downside, however, is that whatever you roll in excess of your mana is taken as hit point damage. Yup, dangerous.
What’s even better, I think this magic system can be grafted onto almost any version of D&D or its clones with ease. Hello dangerous, sword-and-sorcery style magic!