So I was running Pathfinder the other day. The party ended up fighting a Shadow Mastiff. It has the following power: "Shadow Blend, during any conditions other than full daylight, it can vanish into the shadows gaining 9/10 concealment."

I couldn't figure out, by the rules, if it gets this power during combat or not.

I ruled on not, sense it is a CR-5 Monster. It fights about as well as a 5th level cleric and got half the party to panic for 7 rounds with its fear inducing ability.

Anyway, anyone know how it works?

I would assume that if it is fighting, it's not getting the concealment bonus, but I don't know if that's in the rules or not. I would use it more for laying in wait for the party to wander by and such, and if it were trying to escape from the battle.

It is effective during combat.
From the Pathfinder Bonus Bestiary, Shadow Mastiff entry:

Shadow Blend (Su): In any condition of illumination other than full daylight, a shadow mastiff disappears into the shadows, giving it total concealment. Artificial illumination, even a light or continual flame spell, does not negate this ability. A daylight spell, however, does. A shadow mastiff can suspend or resume this ability as a free action.

There is no "9/10" in the text. It's Total Concealment. Now, for concealment, check Pathfinder Core Rules, p. 196-197. You can't attack a creature that has total concealment, but you can attack into the square you think it occupies. A successful attack into a square occupied by an enemy with total concealment has a 50% miss chance (instead of the normal 20% miss chance for an opponent with concealment). You can't execute an attack of opportunity against an opponent with total concealment, even if you know what square or squares the opponent occupies.

Now, pay attention to the next paragraph, Ignoring Concealment. Any concealment is ineffective against opponents with darkvision. A daylight spell negates the ability, as pointed out above. You could also choose to reduce the miss chance for people with low light vision (though the text mentions low light vision, it isn't specific about it, unlike darkvision, which seems strange to me).

Also, notice the low AC of the Shadow Mastiff. It's basically included in the monster's balance for CR 5.

Quote from: Benoist;334857It is effective during combat.
From the Pathfinder Bonus Bestiary, Shadow Mastiff entry:

Shadow Blend (Su): In any condition of illumination other than full daylight, a shadow mastiff disappears into the shadows, giving it total concealment. Artificial illumination, even a light or continual flame spell, does not negate this ability. A daylight spell, however, does. A shadow mastiff can suspend or resume this ability as a free action.

There is no "9/10" in the text. It's Total Concealment. Now, for concealment, check Pathfinder Core Rules, p. 196-197. You can't attack a creature that has total concealment, but you can attack into the square you think it occupies. A successful attack into a square occupied by an enemy with total concealment has a 50% miss chance (instead of the normal 20% miss chance for an opponent with concealment). You can't execute an attack of opportunity against an opponent with total concealment, even if you know what square or squares the opponent occupies.

Now, pay attention to the next paragraph, Ignoring Concealment. Any concealment is ineffective against opponents with darkvision. A daylight spell negates the ability, as pointed out above. You could also choose to reduce the miss chance for people with low light vision (though the text mentions low light vision, it isn't specific about it, unlike darkvision, which seems strange to me).

Also, notice the low AC of the Shadow Mastiff. It's basically included in the monster's balance for CR 5.

That's true. They did eat it up pretty quick for being 2nd level. Thanks for the advice.

Quote from: Cranewings;334860That's true. They did eat it up pretty quick for being 2nd level. Thanks for the advice.

You're welcome! Thanks for bringing this up, as it allowed me to check it out myself.