Martial Arts: Polearm/Quarterstaff/Weapon Adaptation

[(E)]

I'm drawing a complete bank on the terminology but many polearm heads partially encased a fair bit of the shaft. More so with heavier heads.

Personally as a GM I allowed the use of a spear with the staff skill with a change of grip action. But I ruled most polearms where too heavy for the same treatment and only allowed it with the lighter polearm provided the user had specific training such as a martial art. The was a perk from memory that covered changing grips. (Away from books) not sure if it's a published perk though

How you held the weapon was the defining condition.