F4NBOY said:
I feel that it stretches suspension of disbelief in the same way the Vancian and x/day mechanisms do, in that an ability is available a limited number of times without regard for a rest period or what that ability actually is. So, it really brings nothing to the table, in terms of suspension of disbelief. It doesn't even carry over the single semi-charming thing about slots, which is resource management across an environment (i.e. a dungeon delve).
In short, it trades depth of play for a quick fix and an ADD mindset.
I do, however, think that a per encounter mechanism might be appropriate for certain situations and am willing to entertain the idea that it could be revamped to be more broadly applicable.
For example, I think the barbarian rage ability is a poster child for where per encounter is better than a per day. It stretches credulity that a barbarian PC could rage three times before 9:00 am, eat some lunch, get a message, and then not be able to rage at 3:00 pm on the same day; but the next day, he can do a forced march across a swamp and still flip out at 5:00 pm. On the other hand, to say that a barbarian can rage for (level/4)+1 rounds per encounter, every encounter, makes quite a bit of sense and makes it a nice, reliable ability.
To say the same thing about, say, magic missle, doesn't make sense, though. If you know MM, you should be able to cast it. If there is a requirement (slot), then how do you recharge? Can you load multiples? Do you need your book? Can you swap out and how? Why? How much time does it take? If it takes time, why not use that as the balance? If it doesn't, what is the in-character limitation?
Those last two are big ones, IMO. If you have some meta-limitation of "well, it takes 15 minutes for a wizard to reset his focus", why not just use 15 minutes as the key in the first place?
If it really is "per encounter", how does book-keeping differ between multiple rooms of a multi-room encounter (like the new Dungeon Design article) and walking between two rooms with a different key? "I'm sorry, you can't cast magic missle again because these guys were lying in wait while you slew their boss. But, if you leave your party to fight them while you open the next door, you can use it there."
I found it especially disappointing in Tome of Battle because those manuevers were supposed to be non-supernatural tricks learned by the martial adepts. So, why can't I do my signature strike twice, even if I wait a round and do it to someone else? What do these slots represent? The players shouldn't have to parse the meta-system of, "WotC enacted an arbitrary balancing mechanism. Your character still knows how to do that, but chooses not to because the combat should be more interesting."
What is the point of a system that doesn't actually represent what the characters are doing and can do? If WotC goes with more encounter-based abilities (and it sounds like they will), then I hope they address that question and show me how per encounter slots make sense. I'll listen. I just don't actually see how a system like Tome of Battle could do that.
IMO, the per encounter mechanic is one of the very, very few that is more arbitrary, makes less sense, and provides less satisfying game play than the Vancian slots. I very much hope to be proven wrong.