Aijou said:
Personally I miss the old Baldur's Gate and NWN approach to spell balance with Casting Times. I always liked the original D&D approach to spellcasting, where more advanced spells would be hindered by taking a long time to cast and being highly interuptable. Seems much more realistic and interesting to me, and also increases your need to think tactically as a mage.
In pen and paper, at least, this approach is generally non-functional because it eventually winds up being a GM fiat as to whether you get your Uber Spell off or not--your players will figure some way to make it so they can't be interrupted. And then they will get pissed off when you nevertheless find some excuse to interrupt them sometimes. Which will lead to an escalating spiral of quarreling over whether that sleeping guard behind the plexiglass shield could conceivably have heard someone making a chalk drawing . . .
In short, this is usually not an optimal mechanical approach. In a video game, it will have the same effect: the mage annihilates things at extreme range and is fantastically overpowered because the game designer thought that allowing them to (in theory) be interrupted was a "balancing" factor of some kind. The spells themselves need to be balanced, not just the hoops you have to jump through to get them to work. Because when the caster figures out how to minimize the hoops (and they WILL), all you're left with is a pile of horribly OP spells.
Addendum: however, you can get around this problem by having a flat, unalterable, percentage chance that the spell simply Does Not Work. If you start handing out gear/abilities/checks that can alter the percentage, it becomes a major tuning issue, but it can be done.
Additional addendum: btw the absolutely worst implementation of this I have ever seen, ever, is in Exalted, where people using sorcery to cast spells "drop out of the initiative order" while they're casting the spell. We could NOT figure out what this was supposed to mean, it was HORRIBLE. Does that mean that while they're casting, they can't defend themselves? Does their dodge DV drop to zero? Or just their parry DV? Does that mean that the spell is automatically interrupted if ANYONE makes ANY attack on them that gets at least one success? How do you determine when the spell goes off and they drop back INTO the initiative order? It was the dumbest mechanic I'd ever seen. Instead of this folderol about dropping out of initiative, why not just DESCRIBE WHAT THE MECHANICAL EFFECT IS, i.e. they're "flat footed" and it takes X actions to cast? STUPIDITY.
Cooldown meters work well from a gameplay balance perspective, but it makes little sense that it takes my character the same (usually instant) amount of time to cast "flare" and "super killer fireball of armageddon". Though I suppose this mostly relates to the deeper problem of RPGs getting more and more fast paced and action oriented, which I won't get into here.
It takes the same amount of time to pull the trigger on a bb gun and a rocket launcher. Why does it "make sense" that it requires a lot more waving and shouting to cast a bigger spell? In some magic systems, the task you are doing is exactly the same: grabbing some power, shaping it, and hucking it.
And why is this a "problem?" If people really genuinely liked turn-based, then the games would still be turn-based. As it is, some are, some aren't. Options for everyone.