Why is my damage so low?

[Mhaeric]

Potency is the relative power of your abilities, not the actual damage. As you gain more in your main stat (STR for tanks, drg, mnk, sam. DEX for ranged and nin, INT for casters, MND for healers) you will see your actual output increase significantly.

This system has advantages and disadvantages. The advantage is that it keeps it simple to compare abilities and talk about relative effectiveness without the complication of player stats being included. The tradeoff is it becomes harder to know what your actual output will be without actually using the ability. Knowing what your raw damage will be ahead of time isn't that important in this game, though, so the advantage of displaying relative potencies outweighs the loss of displaying exact damage numbers.