| Durfaroth |
I have a bodyguard character which is why I've been trying to find information on Aid Another. Logically, I just couldn't wrap my head around how a character would be able to physically help an ally's defense multiple times for the same attack even though it would help my own character out during play. Multiple character, yes but not a single character. Here is what I found and plan to use personally.
Although not a spell, I would consider the bonus rules from spells to apply here. In the Core Rulebook under Special Spell Effects (pg 208):
Usually, a bonus has a type that indicates how the spell grants the bonus. The important aspect of bonus types is that two bonuses of the same type don't generally stack. With the exception of dodge bonuses, most circumstance bonuses, and racial bonuses, only the better bonus of a given type works (see Combining Magical Effects). The same principle applies to penalties--a character taking two or more penalties of the same type applies only the worst one, although most penalties have no type and thus always stack. Bonuses without a type always stack, unless they are from the same source.
Again, this could possibly be taken out of context since it is found under the guidelines for spells but I don't imagine the mechanic for bonuses would be changed for bonuses not originating from a spell.