I'm designing my own RPG system and I want to avoid the most widely-recognized flaws, loopholes, and exploits that build-point character creation systems usually suffer from.
What are the most common ways players exploit point-based character creation and advancement systems?
So far I have precision based damage limited based on maximum build points so people can't just sink everything into that, and spell level access as well. Actions per round face a hard-and-fast cap at four (there's a base of two), and when switching between 'classes' (essentially just discounted rates on cost for a certain collection of abilities) there's a cost. How much should someone be able to max out their health? Mana? Weapon specialization? Two-weapon ability? I don't need an extensive list, just the most crucial game-breaking things.
My first play-test will be with my friend who is a notorious power-gamer and I'd like to already have the trivial loopholes tied off.