Ok so I know you can enhance your weapons with your arcane pool and it CAN stack. The thing i'm confused about is how it stacks. Here is the actual descrition for it:
"Arcane Pool (Su): At 1st level, the magus gains a reservoir of mystical arcane energy that he can draw upon to fuel his powers and enhance his weapon. This arcane pool has a number of points equal to 1/2 his magus level (minimum 1) + his Intelligence modifier. The pool refreshes once per day when the magus prepares his spells.
At 1st level, a magus can expend 1 point from his arcane pool as a swift action to grant any weapon he is holding a +1 enhancement bonus for 1 minute. For every four levels beyond 1st, the weapon gains another +1 enhancement bonus, to a maximum of +5 at 17th level. These bonuses can be added to the weapon, stacking with existing weapon enhancement to a maximum of +5. Multiple uses of this ability do not stack with themselves.
At 5th level, these bonuses can be used to add any of the following weapon properties: dancing, flaming, flaming burst, frost, icy burst, keen, shock, shocking burst, speed, or vorpal. Adding these properties consumes an amount of bonus equal to the property's base price modifier (see the Magic Weapon Special Ability Descriptions). These properties are added to any the weapon already has, but duplicates do not stack. If the weapon is not magical, at least a +1 enhancement bonus must be added before any other properties can be added. These bonuses and properties are decided when the arcane pool point is spent and cannot be changed until the next time the magus uses this ability. These bonuses do not function if the weapon is wielded by anyone other than the magus.
A magus can only enhance one weapon in this way at one time. If he uses this ability again, the first use immediately ends."
Now it says it stacks up to a max of +5. Does that mean +5 period or an additional +5? The reason I ask is because I am trying to make a Staff magus with this Class Feature:
"Quarterstaff Defense (Ex): At 7th level, while wielding a quarterstaff, the staff magus gains a shield bonus to his Armor Class equal to the enhancement bonus of the quarterstaff, including any enhancement bonus on that staff from his arcane pool class feature. At 13th level, this bonus increases by +3. This ability replaces the medium armor and heavy armor class abilities."
Now at lvl 20 with a +5 weapon and using my arcane pool. Would I have +8 to Ac or +13?
You would have a +8 Shield Bonus to AC.
A weapon can not have an Enhancement Bonus above +5 (with special exceptions for properties like Bane), so you can't use your Arcane Pool to add any more Enhancement to your +5 quarterstaff.
For the enhancement bonus limitation, it depends on the specific effect or ability that's altering the weapon.
Bane: This allows the weapon to exceed the +5 limit, but only against the designated creature type. For example, a +5 dragon-bane longsword is normally a +5 weapon, but has a +7 enhancement bonus against dragons and deals +2d6 points of damage against dragons.
Paladin: The divine bond ability says "These [enhancement] bonuses can be added to the weapon, stacking with existing weapon bonuses to a maximum of +5." That means if a paladin has a +5 longsword, she can't use her divine bond to increase the enhancement bonus to +6 or higher (but she could use her bonuses to add abilities such as flaming to the weapon).
The +10 bonus-equivalent limitation is a hard cap for all weapons; you can't exceed that even with class abilities or other unusual abilities.
As an aside, I love my Staff Magus/Hexcrafter. Staff Magus is a lot of fun to play.
So when it says it can stack it only can make up the difference upto +5 then he can add the weapon abilities after that?
correct
Yes. For example, if you had a +4 quarterstaff and an Arcane Pool that let you add a +3 enhancement equivalent then some of your options would be...
+5 flaming burst
+5 shock, frost
+4 flaming burst, shock
+4 flaming, shock, frost
+4 speed
But you can't use Arcane Pool to have a +6 flaming quarterstaff because that would exceed the +5 maximum Enhancement Bonus limit.
That makes sense... Thanks everyone!!!