
Dorje Sylas |

PRD wrote:
A grappled character who attempts to cast a spell must make a concentration check (DC 10 + grappler's CMB + spell level), or lose the spell.
Note, this is in the glossary under the Grappled condition.
Dimensional Hop is a Spell-Like ability (SP). All rules taht applies to casting spells apply to SPs except as noted in the Magic chapter.
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Yes you can. It takes 1 standard action and you need to make a concentration check equal to (DC 10 + grappler's CMB + spell level)
... or DC 14 + grappler's CMB (should be considered a 4th level spell)
So you can try... but it's unlikely. Although perhaps you'll have a better shot at that then actually breaking the grapple.
(Did we get a ruling on Domain power spell levels for those SPs? Oh I see in the unofficial FAQ )