In a recent game, I had a GM use the Blinding Gaze from the Blindheim every turn. I tried to tell him that it would only work once a round, but it says in the description of the ability it can turn it on and off at will as a free action. I know that some abilities (at least for characters) say that if a creature passes its save it can't be affected again for 24 hours. This doesn't say that. And from a realistic standpoint, if you continually look at a bright light, it can blind you. So it makes sense that it can affect you every round.
But he was having it affect people on every players turn in the round, including the Blindheim's. By the end of the first round (and before most even had a chance to take their turn), everyone was blind except me (Dwarf Cleric-1 with Protection Domain, 18 CON, +1 Fort Trait). I had an 8 Fortitude and wasn't having any problems making the saves. But each round I had to succeed at 6 saves (thankfully I never rolled below a five) and we were eventually able to kill it.
If the ability goes off every turn, this monster is incredibly OP (it may be OP anyways). But I couldn't think where to look in the rules to prove it would only happen once a round. Is the GM right (other than in using his GM powers to do what he wants) or am I?
Gaze abilities affect every creature in the area, once a round, at the beginning of the creature's turn. You shouldn't be making 6 saves a round, your GM was playing this wrong
http://paizo.com/pathfinderRPG/prd/bestiary/universalMonsterRules.html#gaze
Averting Eyes: The opponent avoids looking at the creature's face, instead looking at its body, watching its shadow, tracking it in a reflective surface, etc. Each round, the opponent has a 50% chance to avoid having to make a saving throw against the gaze attack. The creature with the gaze attack, however, gains concealment against that opponent.
Wearing a Blindfold: The foe cannot see the creature at all (also possible to achieve by turning one's back on the creature or shutting one's eyes). The creature with the gaze attack gains total concealment against the opponent.
A creature with a gaze attack can actively gaze as an attack action by choosing a target within range. That opponent must attempt a saving throw but can try to avoid this as described above. Thus, it is possible for an opponent to save against a creature's gaze twice during the same round, once before the opponent's action and once during the creature's turn.
Gaze attacks can affect ethereal opponents. A creature is immune to gaze attacks of others of its kind unless otherwise noted. Allies of a creature with a gaze attack might be affected. All the creature's allies are considered to be averting their eyes from the creature with the gaze attack, and have a 50% chance to not need to make a saving throw against the gaze attack each round. The creature can also veil its eyes, thus negating its gaze ability.
Format: gaze; Location: Special Attacks.
The blindheim can also take an action to make you save again, so that would be twice per round. But then the blindheim wouldn't be attacking; just trying to get in blinds. It's a really nasty creature for its CR. Also beware that there is a 3rd party version that does have the limitation of one blind per day.