Source: modNmod
Related: Curse
New interview with the recently hosted Half-Life 2 mod, Curse:

Q: What kind of magic will you be able to use, and how will it be different from other mods and games in it's class?

Henry: The magic will incorporate fire, water, "pure energy", physical magic, and some of the kinetic powers. The reason why it will be different, is because there is no "mana" or "energy" which limits you in what you can do. There is simply a "charge" function. For weaker charge attacks, it may take 30 seconds to charge it, and while you feel as if you are loosing in a melee battle, you shoot a fireball at the opponent flying him back.

The problem I found in other games that incorporated magic, is that it simply used too much of an effort to destroy your opponent! The reason being? There was no other kind of attacks. This, in my opinion, will be one of the first games to actually use two different ways of attacking, both being equally useful and requiring as much skill the user can get.

Q: Is this mod intended for single-player or multi-player play?

Henry: For the first release candidate, it will be Multi-Player only. For future versions, I, and the rest of the team, definitely intend to incorporate singleplayer. Why? Because who wastes a perfectly unique setting and gamestyle on just multiplayer? You need some scripted action somewhere along those lines.