World without vanican casters?

[ShneekeyTheLost]

Okay, so I had an interesting thought:

What about a campaign in which vanican casting (i.e. spell slots et al) didn't exist?

The 'hybrid' core classes (pally and ranger) don't pick up spells, instead they pick up ToB maneuvers.

Bards become an Invocation-based class. I actually wrote this up a year or so ago. Instead of spells, they pick up Invocations at the same rate as Warlock, although just about everything they did was defined as a Sonic Mind-Affecting ability.

Sorcerers, Wizards, Druids, and Clerics all don't exist.

You've got all the little alternate casting systems out there, Incarnum, shadow paths, psionics, invocations... but you don't have the Big Three.

What would you think about this? Would it be interesting to play?

[The Rose Dragon]

Vancian. They are called Vancian casters.

It was done before, actually, on these very forums, with a game where you were mostly limited to psionics, Tome of Battle and Tome of Magic. I don't know how it worked out.

[Snake-Aes]

It depends mostly on the taste of your players, really. Without the big vancians, it's probably a bit easier to manage challenges too. If the players don't mind playing without vancian magic, then removing it completely doesn't detract from the gameplay experience.
(True20 and StarWars have an interesting casting system based on skill checks and nonlethal damage if you still want the old spells accessible. That way it's accessible to anyone but casting classes would have an edge)

[The Rose Dragon]

Speaking of True20, you might want to look at True Sorcery by Green Ronin for an alternate approach to spellcasting.

[AmberVael]

You've got all the little alternate casting systems out there, Incarnum, shadow paths, psionics, invocations... but you don't have the Big Three.

What would you think about this? Would it be interesting to play?

Well, given that the campaign setting I made is based on this concept, I think my answer is pretty obvious...

I also took out Psionics though, since it tends to be higher tier than the rest of the remaining stuff.

Edit: I also removed a few other things in order to mostly shift mechanics towards per encounter rather than per day, and in fact, there is one class that still uses spells (Factotum). But it's mostly what you're thinking about.
The mechanics section definitely still needs a ton of work though, given everything I am trying to remove.