What are some strategies that I can employ to handle a power gamer that constantly outshines the rest of the party? This is a friend of us all and we don't want to boot him, but combat simply isn't fun when the party has nothing to do while he mops up an encounter by himself.
Does he know there's a problem? There are plenty of mechanical ways to limit his character, but bear in mind that you may wind up moving the frustration from yourselves over to him. And if he's at all smart, he's going to recognize what's going on.
My generic answer for problem behavior is "talk to the guy," which is harder but often more effective.
I really dig the idea of giving him bigger monsters to fight. Obviously being awesome is part of what's turning his crank; if you can figure out ways to let him show his awesome without overshadowing everyone else, that's a win for everyone.
You can do a very nice trick. Talk with him and with his consent entrap him into a lesser character.
In normal gameplay, the player plays the lesser character. However, once per day, he can try to "morph" back into his (e.g.) human form for a reduced amount of time (like one or two hours, with increasing difficulty for every additional hour to keep staying in normal form) via a willpower saving throw. Have it based on the willpower of the original character, not of the lesser one, and make it with a difficulty so that he succeeds in one case out of four. If he fails, the lesser character loses consciousness until the end of the encounter. Note that this strategy is very similar in concept to the Space Ace "Energize" option.
I already tested with strong success this strategy. In my case, it was a very powerful 10th level warrior hosted into the body of a kobold. The backstory is that the character was part of a dragon-slayer guild, and one dragon was able to beat them. He was the only survivor, and was cursed into the most repulsive and insignificant reptile creature, a kobold. This kobold saves the party of 1st level characters from an ambush, and joins them because he is a smart but very goofy sorcerer and tool-builder of his tribe, outcasted due to his tendency to attract troubles.
I'm not a power gamer myself
That may be part of the problem. You appear to want a game that is ill-suited to power gaming, while he seems to want very much to min/max, optimize, and otherwise employ power gaming techniques. Maybe the two of you need to discuss what sort of game each of you wants, and bring the other players into the conversation as well.
Have the discussion before the game session starts, and preferably in person. Email can easily be misinterpreted. It's OK to have this sort of meta discussion, and it becomes vital where there's a potential mismatch of expectations.
If the guy likes a challenge, ask him to play and optimize substandard builds via awkward race/class combinations or weird flavors and themes. The artificial handicap is optional and can scratch the powergamer itch without blowing away the other party members. Doing this may edge him into more RP interesting characters as well.
If you're playing with a system that rewards character optimization, I don't understand how "power gaming" - within the letter and spirit of the rules - isn't simply good play. Why would you penalize a player for intelligent use of the rules? Would you penalize a player who's a good combat strategist just because the other players aren't as good at it?
It seems like many games are structured so that some options stack with other options to give great mechanical advantages to players who discover the combos. It also seems like part of the fun, for some players, of playing those games is discovering and implementing those combos. If you and the other players are uncomfortable "keeping up" with the power gamer, then it seems like the problem is either the system or the compatibility of the group.
I wouldn't run a game with a crunchy, combo-heavy system if I were uncomfortable with players optimizing character builds. Being penalized for intelligently using the system would have to be maddening - metagame "revenge" for intelligent play reeks of Ear Seekers.
Make sure your campaign isn't all about combat. Have situations where even if you kill everything the problem/issue isn't resolved. Also provides some context for all the characters. For example a cleric would be associated with a temple, an ex-navy engineer have some navy buddies. By playing to each of the character's backgrounds in turn you create opportunities for them to shine.
Build the encounters to match your player group. If you have 4 decent players and one power gamer throw in a group of weaker enemies with a powerful leader. Such that the power gamer has no choice but to engage the more powerful enemy while the others take care of the others.
Perhaps a group of skeletons being bossed around by a Skeleton Warrior, or a Lich, (not sure what level range you are going for.)
for lower levels throw in some Orcs with a troll for reinforcement. Something to keep his attention while the others still have fun.
Basically balance the enemies to your players.
IMHO is a typical problem caused by the GM: let me explain.
One of the PCs is very successful at doing something, and the other characters are not. This can be a problem only if the other players are bothered by the situation.
If nobody cares and everybody has fun, keep on going.
Else the solution is either to make sure everyone can have fun. Go read something on RPG players types and craft your game so that everybody can have their share of fun. Customize your game for your group: the power player can have lots of hard fights while other players can have fun other ways.
And there are always combat situations like a really strong subject needs help from weaker subjects: tanks without support from infantry, artillery and aviation are not as strong.
Your tank might have the ubergun and the awesome armour and be fast as heck, but he needs enablers. And make sure enablers don't strictly need the tank to succeed/have fun. A tank is useless outside of the battlefield :)
Again: the source of the problem is the character in your game, not the character in isolation.
Aside from Bryant's good suggestion to talk to the guy, you can also study this powergamer's character for what his weaknesses are and take advantage of them. For instance, I once had a player in my D&D 3.5e game who could hit for tons of damage, but he had to recharge the attack, and that provoked opportunity attacks. So, I started to work my future encounters so that he was always at least double teamed, and when he had to recharge he was in danger of multiple opportunity attacks.
Another suggestion is to limit what your characters can use to create their characters. If your powergamer is taking advantage of multiple splatbooks to create their character, you could institute a 'one splatbook per character' rule where each character can only use the core rulebooks and at most one splatbook to create their character.
In addition to the good suggestions already offered...
I would encourage you to offer that player something better than the opportunity to happily smash each and every bad-guy/thing/lich with halitosis: offer him rich role-playing, and reinforce him positively when he embraces it (in-game with rewards, above-game with comments of appreciation like, "What a great decision! That was just exactly what your character would say! Love it, man!"). Reinforce, encourage, and get the rest of the group to do so, too.
Sure, it may take a while for this person to transition from munchkin to a role-player who's happy to play a narcoleptic thief with severe allergies and palsy...but everybody's got to start somewhere, right?
Of course, this is so easy to answer because none of US have ever been the munchkin, have we?
Answer is simple, put them in environment where their skills are useless, for example force them to do more thinking less using their "skills".
This is reason why I prefer weaker characters. Those players think more when they playing. If you want to have well balance team, try to make characters by your own and tell players to use them. Last thing, at the end of the day, you are GM, you can say I don't care if in XXX manual was written, I'm GM and I don't allow that because this is breaking my concept of world.
Another option is to have maps that have terrain that helps some of the other character's power sources, thus making them more effective, but keeping him the same. You will be able to have stronger enemies (maybe with reduced XP since there is a conditional buff for the PCs), he'll be dealing the same awesome damage as before, and the rest of the party should be on par with him as well.
If, having talked to your power gamer, you find that it's part of playing that they like and you don't want them to leave then you need to cope with it.
Is it a problem to have one character a little more powerful than the others? If the character is min-maxed then chances are it is toward a specific goal. As long as the group's goals are varied enough, then the affect of the power gaming is reduced. When their talents do come to the fore then let them have their moment of glory.
Min-maxed characters tend not to be overpowered when it comes to narrative situations, so you could use more of those.
If they find a major abuse of the rules then you can congratulate them, give a different bonus as a reward for finding the flaw and then houserule the loophole away. Ensure you give them a reward, though because finding a loophole is quite a clever thing to do!
- Talk to him and see if this is a result of previous bad GMs killing him off. Assure him you won't do this.
- Make combat easier. Abstract these encounters to little/no rolling. Your player gets to be awesome, you don't end up wasting time on him slaying little minions. (Keep the big fights big though, only do this for small encounters).
- Make combat secondary. Design encounters that have goals other than "kill all the things." Heists, hostage situations, burning buildings with people/paper objects in them, etc. Put enemies in there but make it obvious that time/other factors are the goal.