Vault Dweller and Gareth Fouche put up their thoughts on spellcasting in CRPGs.

<p style="margin-left:50px;border-style:solid;border-width:1px;border-top-color:#ffffff;padding:5px;border-right-color:#bbbbbb;border-left-color:#ffffff;border-bottom-color:#bbbbbb;">We can see from these examples that the computer has great potential for immersing the player in spellcasting beyond simple casting bars and mana pools. Interesting interfaces and systems which encourage the player to experiment with magical forces, rather than simply buying spells from a list, result in players becoming more invested in the process of spellcasting and help to truly differentiate the mage player from the fighter or stealthy player. These exploratory systems, combined with an interesting 'mage path' through the game, a path that sees the player negotiating with spirits, learning dangerous and forgotten secrets and interacting with the environment and other characters in unique and interesting ways, have the potential to create a truly memorable mage experience.

They mentioned some good examples.

Spotted at: ITS