First, let’s go over the basic concepts:
In a magnificent game such as D&D 3.5 or the excellent child called Pathfinder, the most effective and fun gaming occurs when every player has a decent understanding of “roles.” The game is simply constructed so that characters are more effective when they specialize in an area. It comes of the construction of the fantastic character-building system, where the player chooses from among a number of abilities and options, so that they build a particular type of character. This is not to say that you don’t want to build a character who isn’t effective in all types of situations. Instead of a truly “well-rounded” character however, you should look for a “well-lopsided” one. Fulfill a role while paying a due to other options, so that you are never at a loss or a drag on the game.
Not only does planning for roles make the characters more effective, but it makes the game much more fun as well. As human beings, we simply don’t function well when everyone talks at once. The GM can only pay attention to a couple things at the same time, and if someone is speaking to him or her, describing their character’s actions, the GM cannot be dealing with another person doing the same thing at the exact same time. Combat is constructed as a series of turns for this very reason. Therefore, characters need to take turns in the spotlight, and need to be depended upon to make the most of that spotlight while they have it. Understanding your role in the party only becomes more and more vital as the game goes on, when players become more invested in the story and the power of the characters and monsters increases.
Rather than discussing the commonly-accepted names for roles that are out there, we will look at each of the 9 base classes in the core rulebook, and discuss where each one excels and how they can fit into the party structure.
Your friends will rely on you to be a brute. You can take damage, and with a bit of character planning you can really dish it out. You have an edge of speed and versatility that means you are someone who can get to where the fight is at, strike a serious blow for your side, and just keep on going when the enemy hits back. You need to make sure that you are getting attacked.
One of the most deeply controversial classes in terms of role. I do not subscribe to the concepts that the bard is a “jack-of-all-trades” or the “best fifth character.” Instead, the Bard is a subtle character whom the party will come to rely upon. Your teammates will rely upon you to give them a vital edge in combat, making them all more effective and backing that up with important spells. They will need you to take the lead out of combat, with an array of knowledge and social skills that can win fights before they start.
Your party will rely on you for healing. However, you keep everyone alive in several other key ways as well. You have access to vital magic that no one else does. You can wear serious protection and you can more than hold your own in a beatdown fight. You will be relied upon to plan ahead with your defensive and offensive magic, and take your knocks as need be.
Your friends need you to have a bit of healing, a bit of defensive magic, and a whole lot of extra pals. You can bring more key helpers to the table than anyone, and it’s vital that you do so while blasting away with other magics. You can also set up to fulfill key damaging roles in hand-to-hand combat, with a whole host of options that you can pick up at the last minute. Always be looking for the perfect option for the next encounter, as you will often be the linchpin upon which the wheel of the party turns.
You can fulfill several different roles, depending on a wide array of character-building choices. Your party might depend upon you to be the toughest, hardest-to-kill member and direct all the enemies toward you. You might be relied upon to put out the most serious weapon damage. In all, the fighter needs to have a very strong understanding of the “well-lopsided” concept and build his character toward that ideal.
Another somewhat controversial class who can be absolutely vital. You will be needed to get to the fight before anyone else, survive all the way to that point, and be effective at locking down the enemies when you get there. As soon as you stop playing games where all the fights take place in big, empty rooms with a bruiser enemy, the role of the monk becomes clear. You need to take care that you are at the right place at the right time because no one can do that as well as you can.
You will be relied upon to rank among the toughest warriors out there. You’ll need to do a little healing and backup spells in a pinch, but your focus needs to be taking on the most dangerous and the nastiest of the evil damage-dealers. You have the survivability to outlast, and you need to make sure you’re the first into the fray and the last man standing.
The ranger needs to be the man with the plan. You need to utilize your woodcraft and your expertise in certain enemies. You have some backup healing and spellcasting, but you bring your seen-it-all type of abilities to the fore and your damage-dealing focus needs to be chosen carefully to play off the other players. If there’s another melee type with a dangerous full attack, you should probably choose a ranged style, and vice versa. Err on the side of ranged damage or on being extremely tough.
Another extraordinarily versatile class, the two things you will definitely be relied upon for are dealing with traps and being stealthy. You should build your choices to deal damage and to improve your capability in your roles, as well as bringing a whole host of skills to the table so that you are truly never at a loss. Be careful about survivability, and be the person with a backup plan.
A somewhat problematic class if you’re overly fond of comparisons with other classes. Nevertheless, the sorcerer will be relied upon for two vital things: versatile on-the-fly spellcasting, and not running out of spells. Make sure you can keep slinging those spells one after the other, and that those spells each have greatly varied uses. You may want to look into the gamingmage variant sorcerer, presented here.
You will be relied upon to have the perfect spell for every encounter, day after day. Attempt to evince a nigh-supernatural ability to pick the perfect preparations, and control reality with a number of different specializations. You will be relied upon to deal with large numbers of enemies, to give your companions an edge, to win the fight before it starts, and to match the spells being thrown at the party with magic of your own. You can cherry-pick the ideal spells, and you should try to do just that. You will also be expected to make possible all the things that were impossible without you.
Don’t disappoint your party members with poor planning. You should ask questions at the beginning of a campaign, and get an idea of where everyone is going with their design. While you want all the possible required roles to be covered, you need to make sure that you enjoy and can shine in the roles you’ve chosen to excel in. Be open about your choices, and the possible side paths you might consider later on. And make sure it’s going to be a fun, well-meshed party.