After many experiences playing roleplaying games at cons, more recently playing D&D Encounters, and playing with a few gaming groups I didn't know too well, except for maybe a person or two, I've made some observations about game play and advice on how best to enjoy sitting down to play an RPG with strangers
When it comes to playing with strangers, you don't know what the player dynamic will be, and you won't know what the GM will be like. If you're playing a dice heavy game like D&D, which can easily turn into a hack-n-slash game, if you're prepared for that happening, you have a much better chance of having a good time. If it's a new group you're playing with, and it turns out the game isn't hack-n-slash at all, you could always change your character later.
The basic rule is that you shouldn't build a character with finesse in mind. You essentially want one of two kinds of characters:
- A tank. A character that can take a lot of damage. Typically you'll be spending a LOT of time in combat in games with strangers, and you'll need at least one character that can do this. The rest of the party will be in awe of your damage absorbing abilities, and you'll feel good about providing this role. It is satisfying to be effective. Characters like this usually aren't bad at dealing out damage as well.
- A character that can dish out a lot of damage. Again, you'll be in a combat constantly. Doing something useful, like dealing out a lot of damage will be satisfying, and you and everyone else will be in awe at the damage you deal out. I don't even recommend choosing magic users for this kind of role, since they usually can only deal out a lot of damage in specific situations, or for a limited number of times. Maybe 4th edition evened out the classes a bit in this regard, but for 3rd edition I think staying away from a wizard, since you're probably playing at a relatively low level, is a good idea.
The very last thing you want to be is a Rogue that relies on stealth. I've seen so many games where the party decides on a plan, one that requires stealth. Then one of the players decides that since they're playing a headstrong fighter, rushes into battle disregarding the plan. The result is always the same. The player playing the rogue is frustrated because they didn't get to do any of the cool things they were hoping to do with the character they built, and is frustrated because they can't contribute nearly as much to the brawl that ensues. When a player rushes into battle without any regard for the skills of their party-members, the rest of the party always follows. Always. I'd love to see a game where the party just stands back while the player that rushed off finds their character fighting all alone, but I never have. I should add that this behavior is always explained as a form of roleplaying, though it hardly strikes me as such. In any case, a player like this gets to dictate the way the whole game is played, and if you're sitting in a table with strangers you either have to get up and leave, or stick it out. If you build a character that can work in a game like this, you can end up having a good time.
(I can't help but mention this bad experience I had, especially since it wasn't a D&D game: I've played a Battlestar Galactica game at a con where the mission involved 2 pilots, and a group of marines. The mission was designed entirely for ground combat, so only the only thing the pilots were useful for was dropping the party off at the beginning of the game, and flying away at the end. I feel sorry for the people who played the pilots (like me) because they had nothing to do all game. The guys playing the marines seemed to have fun blowing everything up though...)
Basically, I'm saying that in a game with people you don't know, a simple character that can take and/or deal a lot of damage can work with the widest variety of players. It'll never be useless.
The other thing, and this is a wide criticism, is that D&D and games similar to it seem to really stifle creativity. They don't usually reward players trying creative things to do with their powers or skills. You'll often find yourself punished by terrible dice rolls when trying anything interesting or different. I've found D&D 2nd edition to be better when it came to this problem than 3rd or 4th editions, maybe because it doesn't try to model as many things with dice as the newer editions do, leaving more to the imagination. (Or maybe it's just some kind of je ne sais qua?) But that's been my experience. A good GM can definitely mitigate this problem which is inherent to games like D&D, but when playing with people you don't know, you can't count on that. I think a straightforward character of the "I hit things and then they die" mold works best since you can get creative with a character like that when the opportunity is there, but can be effective even when it isn't.
I should make overt the following point: you really do feel better when your character is effective in a hack-n-slash game, and in a game with people you don't know the game can easily BE a hack-n-slash game regardless of how it's advertised or perceived by the players. So the easiest way to do be effective is to make a simple character that is all about hurting things, or being hurt and staying alive.
Of course, most or none of this applies to more interesting or quirky games than D&D which are often played at cons, with strangers. The more intrinsically roleplaying oriented a game is, the less these observations hold and advice matter. And I'm not saying that all D&D games are the same...just that a lot of them are. And I'm not saying that a hack-n-slash game can't be fun - it can be.