The answer may seem obvious, but I am unsure of it.
Is someone with the pinned condition able to attack his grappler ?
If that attack's possible, does it incur any penalties ?
Pinned: A pinned creature is tightly bound and can take few actions. A pinned creature cannot move and is denied its Dexterity bonus.. A pinned character also takes an additional –4 penalty to his Armor Class. A pinned creature is limited in the actions that it can take. A pinned creature can always attempt to free itself, usually through a combat maneuver check or Escape Artist check. A pinned creature can take verbal and mental actions, but cannot cast any spells that require a somatic or material component. A pinned character who attempts to cast a spell or use a spell-like ability must make a concentration check (DC 10 + grappler's CMB + spell level) or lose the spell. Pinned is a more severe version of grappled, and their effects do not stack.
It's not explicit, but my reading is that the "few actions" that a pinned character can take are spelled out: attempt to free oneself, use verbal/mental actions, cast spells or SLAs without without somatic or material components only with a Concentration check. So no, no attacking while pinned; you have to get free first.
Pinned: A pinned creature is tightly bound and can take few actions. A pinned creature cannot move and is flatfooted. A pinned character also takes an additional –4 penalty to his Armor Class. A pinned creature is limited in the actions that it can take. A pinned creature can always attempt to free itself, usually through a combat maneuver check or Escape Artist check. A pinned creature can take verbal and mental actions, but cannot cast any spells that require a somatic or material component. A pinned character who attempts to cast a spell must make a concentration check (DC 10 + grappler’s CMB + spell level) or lose the spell. Pinned is a more severe version of grappled, and their effects do not stack.
Looks like the pinned can
1) Attempt escape via CM or Escape Artist2) Take verbal/mental actions
3) Cast a spell that has no somatic or material components.
That's it. Nothing else.
Thanks for the answers !