Several of my friends are starting a game pretty soon, and one of the players is a great guy, and fun to play with EXCEPT, he plays with the objective of optimization, while everyone else plays much more casually. He knows his stuff, and is always cross referencing books, and sometimes that can be a good thing, but he tries to make his character as overpowered as possible. I haven't played with him in about 4 years, but back then, I was typically the DM, and even when I tried to tell him he couldn't do something, he typically was able to defend it by proving it was within the rules of the game. Of course, being the DM, I could have just told him I wouldn't allow it, or killed off his character or something, but he was usually right. To be fair, if I could find that it broke a rule, or if I really put my foot down, he'd comply, and was good natured, but I always felt that I was treating him unfairly since I never told anyone else that they had to change their character. I'm not DMing this first game, but we usually rotate, so I suspect I will soon (especially since I was the default DM in the past). Not sure if this is relevant, but we are playing online (for geographical reasons), and starting at level 5. He tends towards druids and clerics.
Although I understand that playing the optimization game is perfectly valid, it isn't a good fit for our gaming group, as he tends to overshadow the more casual players and is not driven by the same goal.
That said, what can I do, both as a player and Dungeon Master to keep him from over-optimizing (i.e. overpowered character builds), derailing the plot, and other general mischief?
To be more specific, his goal in the game is typically to see how much he can get away with. His MO is:1) to find ways to make characters that do tons of damage, and are difficult to damage back, and 2) to try to find his way around plot points, which puts the DM in the uncomfortable position of improvising major plot points.
- He was playing a cleric, and everyone else was expecting him to be support, healing, etc. Instead he built a tank that was doing more damage than the Warblade, or the barbarian, and was using his healing on himself, so he never dropped more than 75% HP.
- While the rest of the party was still in combat, he entered a room which I had intended for the entire party to enter at once. The person in this room had valuable information about the quest, but after learning that information, he promptly killed the NPC, leaving him as the only one with this knowledge.
What is a good motivator for a player like this to work well with the party and actually try to achieve the goal of the campaign?