I guess this question boils down to whether bonuses that do not clearly have a declared type are considered to be untyped and there stackable.
I'm trying to build a character who has numerous bonuses with Bull Rush. Here's what I have:
+2 from Dwarven Boulder Helmet (Circumstance Bonus)
+2 from Heirloom Weapon (Trait Bonus)
+2 from Improved Bull Rush (Feat that does not specify the type of bonus)
+2 from Relentless (Alternate Dwarf Racial Trait that does not specify the type of bonus)
Helmet, Dwarven Boulder: This heavy, reinforced helmet can be used to make melee attacks. The wearer may also use the helmet when attempting bull rush maneuvers, granting a +2 circumstance bonus on the check, but after completing the maneuver (whether successful or not), the wearer is staggered until the end of his next turn. In addition, the helmet grants a +2 circumstance bonus to the wearer's AC against critical hit confirmation rolls. A dwarven boulder helmet adds 20% to the wearer's arcane spell failure chance. It occupies the head slot and is made of metal, not stone, meaning that it can be crafted from unusual materials as a metal weapon. A dwarven boulder helmet can be enchanted as a weapon (not as armor, despite providing some protection).
Heirloom Weapon: When you select this trait, choose one of the following benefits: [...] a +2 trait bonus on one kind of combat maneuver when using that specific weapon.
Improved Bull Rush: You do not provoke an attack of opportunity when performing a bull rush combat maneuver. In addition, you receive a +2 bonus on checks made to bull rush a foe. You also receive a +2 bonus to your Combat Maneuver Defense whenever an opponent tries to bull rush you.
Relentless: Dwarves are skilled at pushing their way through a battlefield, tossing aside lesser foes with ease. Dwarves with this racial trait receive a +2 bonus on combat maneuver checks made to bull rush or overrun an opponent. This bonus only applies while both the dwarf and his opponent are standing on the ground. This racial trait replaces stability.
...so, I guess my question is whether Relentless is untyped, racial trait, or trait. It appears untyped, but I can't imagine why this would be the case. It is a racial trait, albeit an alternate one, and most other racial traits specify their bonuses as being racial trait bonuses. There isn't even another dwarven racial trait that Relentless could conflict with. The language used on Relentless is basically the same as Improved Bull Rush, which clearly is untyped so that it can stack with Greater Bull Rush. In short, do all of these bonuses stack, and does anyone have any suggestions for similar Bull Rush bonuses?
