Embolden is the other reason RDM has lower DPS than either SMN or BLM, a 10% increase of physical damage for 5 seconds that's scaled down every 5 seconds, the only people this doesnt effect are the healer, but if you time embolden right to go in burst windows, its huge damage.

You also have to realize how mobile RDM is compared to the other 2 casters, it can move for free ever other GCD