Cameron said:
It is banned in NWN because of the way NWN works. Everything is biased towards melee combatants. It is almost impossible to come up with the 101 tricks that most Wizards can have that virtually ensures a melee artist never reaches them in pnp play. To date, the character that had the easiest time finishing the game is still my TWF Longsword wielding Fighter/RDD.
Using NWN as a basis for power in pnp play is a very bad idea.
The RDD as is is a warrior-type prc. In order to make it more caster friendly, change the extra spell slots to +1 caster arcane level. That should balance things out.
I'm not using it as a basis for power, I put the math right there. That doesn't change any of the mechanical advantages, I was just using the NW example for frame of reference.
It is good as fighting classes go, I do have experience with it. Wizards at high level get many tricks, it is true (illusion and polymorph and instant-incapacitation effects oh my). I would never say that any core melee class is better than or even equivalent to a caster from levels 10-25 or so. Past that the save DCs start to suck.
Look at it this way:
Class gains improved toughness twice (ie 2 hps per level over a fighter)
Class gets Fly at will as an EX ability (not quite, but close to)
Class gets permanent EX mage armor (slightly better than, actually)
Class gets a double strength bull's strength, permanently, that stacks with all other enhancements
Class gets 2 good saves
Class gets immunity to several effects
Class gets a variety of bonuses to other, less useful stats
Class gets 3 vision modes.
If you saw a prestige class that granted that, wouldn't it look good for a meleer?
I'm not saying wizards aren't awesome. They are, because they can incapacitate an opponent easily in one go. Clerics yet better, due to their enhancements. However, the dragon disciple is a good class in it's niche, and since that's all there really is to go by, a good class by extension.