The Rules Lawyer is that generally derided species of gamer who seems to know (or thinks they know) the rules better than anyone else. Every group or club has at least one example. According to popular legend their sole purpose in life is to ensure that no one has fun at a game because they have discovered every loophole in the rules and twisted everything else to fit their warped, sometimes megalomaniac, gaming style.
Of course if this were true then why would anyone put up with them? I suggest the reason is that the Rules Lawyer actually enhances a group and raises the game of the other players. Controversial, maybe, but as we shall see they do have a purpose aside from striving for world domination through intimate knowledge of the rules.
There are two basic types of Rules Lawyer but their natural habitat and prey are essentially similar. First is the traditional Fun Vampire, the type that know every rule no matter how small and, given the space, will argue their point till everyone else either agrees with them or commits Harakiri through boredom. The other type is the Bullshit Salesman who actually know less rules than the average player but pretend they know more than anyone else. they usually communicate this fact by sighing dramatically and rolling their eyes in mock disgust. Ironically only the Fun Vampire can vanquish the Bullshit Salesman quick enough to save the game.
How can these players (if they can be called that because they spend more time Lawyering than playing) be a good thing? I've read lots of advice on how to deal with Rules Lawyers but in my humble opinion it comes down to just two things. How you (the player) deal with them and how the GM deals with them. First lets look at the GM's role.
The GM also has a large role to play in controlling the Rules Lawyers. One of the best bits of advice I have ever read suggested challenging the Lawyer to find the rule they are quoting, but they have to do it on their own time. In other words they have to step outside the game while the rest of you get on with play and they cannot rejoin the session until they either back down or prove their point in the text of the rules. But the GM must be firm and set some clear house rules before the campaign begins. It helps to clearly define which rulebooks are in and which are not and stressing the GM's decision to use a rulebook is his alone. The GM shouldn't ignore the Lawyers protestations - he might actually have a point -but once a ruling has been made it should be clear the GM's decision is FINAL!
As a player, if you let the Lawyer annoy you or wind you up, they have won already. The moment you loose your cool you also loose the initiative and you make the Lawyer the centre of attention (which what they actually crave more than anything else). But if you can control that desire to rip their throat out with nothing but a sharpened d20, you have the upper hand. Nothing frustrates a Rules Lawyer more than the patient forbearance of his fellow gamers. Its also vital that players abide by the GM's house rules as defined above. Dissent will be leaped upon by the Rules Lawyer and pretty soon the game session will descend into a messy argument.
But for Players and GM's alike another good bit of advice is look on the Rules Lawyer as a useful resource. If they are of the Fun Vampire variety and actually do have an encyclopedic knowledge of the rules use that expertise. For example if the GM wants to introduce a new house rule, ask the lawyer do look at the implications of that ruling. Or of a new rulebook or supplement is brought out, use the Lawyer to review it and make his recommendations to the GM on inclusion or exclusion. What the GM is doing here is channelling the Rules Lawyers natural tendencies and employing them into an advisory role. The GM needs to maintain his authority on the final decision but that does not preclude taking the Lawyers advice from time to time.
The Rule Lawyer in his wild and untamed from can be a game killer. But when controlled and managed properly they can be a force for good in a group. Their pedantry can actually raise the game of the whole group and certainly makes player interactions more interesting.