How many times per round can I use the goblin racial feat Roll With It?

Question

How many times per round of combat can I use the Goblin racial feat Roll With It?

The feat itself does not specify once per turn; however, I have had it ruled both ways in the past, and am simply looking for clarification.

For example, if a goblin is struck in melee combat and succeeds the acrobatics check, does he:

1. Roll the distance (provoking attacks of opportunity) and simply stop moving once the distance is reached?

   or

2. Roll the distance (provoking AoO) and is allowed additional acrobatics to continue rolling, thus causing a "pinball" effect until he stops?

Note: Links to such rulings restricting the usage of feats multiple times would be much appreciated.

Answer 1

Once per round.

Activating the Roll With It feat requires the creature's immediate action, in response to being hit by a melee weapon. The Acrobatics check is part of this immediate action.

If you are struck by a melee weapon you can try to convert some or all of that damage into movement that sends you off in an uncontrolled bouncing roll. To do so, you must make an Acrobatics check (DC = 5 + the damage dealt from the attack) as an immediate action. If you succeed in this check...

Creatures typically get one immediate action per round.