Ok, I'll do what I can to explain it.
Let us use dark heresy as an the example game.
Assume for the following example that the techpriest upgrades the exact same stats, the exact same way.
Say we have tom the techpriest. Say he builds up his backstory as a noble and a duelist. He has good
WS,
BS and asks to be a fellowship techpriest, a diplomat of sorts. He gets special advances and the ability to upgrade his fellowship. This makes for a good, unique character. Now if this same character doesn't adhear to his backstory, picks up a multi-laser and only uses his fellowship to lower prices on items... we have power-gaming. (actual player character
btw...)
However, let us say tom the techpriest keeps on his path of sword and pistol. He speaks for the party a good deal, and tries to challenge foe's to one on one combat. He may, through roleplay, be able to get certain talents that match being a two weapon duelist, that his class wouldn't allow him to get normally. He becomes a beast in melee, and uses his noble influence to get some of the best swords and pistols around. We have a good roleplayer that is maxing himself out.
That in a nutshell is the overall difference. If you roleplay it right, but still keep your characters strength maxed, you have roleplay min-max. However, if you just take the best crap and say screw your characters background, making no effort to explain why you needed to buy that missile launcher as an adept or why that cleric needs a rad-clenser, you have a powergamer who is min-maxing.
Basically, both players are still min-maxing, but for different purposes. You wouldn't want to play a character that was completely ineffective, and the roleplay min-maxer finds a way around that. For example I played way back in 2nd edition
dnd a character that was exceptionally dumb, but found throwing bucklers to be effective. My
GM allowed me to focus on that, so I was a shield chucker for a good long time, taking penalties to some things to gain bonuses to what I wanted to do.
For a final example, upgrading toughness in dark heresy is something of a standard, but if you have a low strength, shooting only techpriest with very high intellegence who takes a mining augment for it's bonuses to toughness and makes no use of it otherwise, besides the off chance you need to drill something, your powegaming unless you have a valid, roleplay reason for the change.
Captain Idaeus wrote:I have no problem with character optimization, that's not what I am trying to get at here. What I am irked by is when my low level pc's who are supposed to be just above average and fairly squishy eat daemons for breakfast.
If that is the case, then do what I have implemented. I state you cannot purchase anything beyond the first two stat upgrades without a valid roleplay reason. You cannot, say, have an adept who spends the whole game reading and researching and then uses his experience to purchase the 3rd toughness upgrade. You may want to go as far as to state that you cannot advance your still that quickly, or just limit when stat upgrades can happen.