A friend of mine was puzzled by the whole idea of tabletop RPGs, so I thought I'd give a little example of how such things work. We'll use the "Dungeons & Dragons" game as our example, since it's the most popular one out there (and pretty darn entertaining, too).
-=-=-=-=-First, imagine a bunch of people sitting around a table. We'll call them Anne, Bob, Calvin, and Dennis. On the table there are hardcover rulebooks, paper, pencils, and some funny-looking dice.One of the players (Dennis) is the "Dungeon Master," or "DM," and he creates all the content and problems in the game, often on-the-fly. The other players (Anne, Bob, and Calvin) play the roles of different fantasy characters. These characters are called "player-characters," or "PCs," to differentiate them from the characters the DM makes up.To make things simpler, we'll start in the middle of the action. The PCs have been sent on a mission by the priests of Pelor to retrieve a potent holy artifact that has been stolen by a band of bandits. After some investigation, they are nearing the ruins of a church where they suspect the artifact is held.
Dennis: It's a cloudy night. There are shadows all around you as you walk into the town square. The church, according to your map, is about a quarter-mile away, at the end of the main road. Decrepit buildings on either side seem to hem you in. What do you do?
Anne (who is playing an elven wizard named Elanna): Is there any sign of life here?
Dennis: Not that you can see.
Calvin (playing a cunning thief named Rovan, who is along for the ride because the bandits reportedly have their big stash hidden in the church): Hmm. Why don't I search the neighboring buildings of the town for some...supplies.
Anne: We've got better things to do than loot abandoned houses, Rovan.
Bob (playing a tough-as-nails dwarf fighter named Kelgan): Bah, enough of this mulling around! Why don't we go in to that church and hit these bandits head on?
Anne: Fine with me. As long as the dwarf's in front.
Calvin: All right. Let's get this over with. I guess the real prize is in there, anyway.
Dennis: Okay. You are right outside the church now. The building's in bad shape - the thatch roof is almost completely gone. There's a lock on the front door.
Calvin: I can handle that. I'm gonna try to pick the lock (rolls a 20-sided die and gets a 16). Okay, 16, plus 9 from my lockpicking skill, for a final result of 25.
Dennis: You deftly manipulate the crude tumblers in the lock. The hasp comes off with no trouble. Kelgan, you want to open the door and go in first?
Bob: Let's go. I draw my axe. I'm gonna kick the door in.
Calvin: I'll stand a ways back, with shortbow at the ready.
Anne: I cast Mage Armor on myself. Time to get my hands dirty, I suppose.
Dennis: Okay, with your heavy dwarven boots, you kick the door in (Rolls some dice and notes the result). You manage to surprise two shabbily-armored bandits, who have their swords drawn but weren't expecting you to come from their locked front door. You can act before them. What do you do?
Bob: I'll charge the lead bandit and swing at him with my axe (Rolls die). A final result of 24! Does that hit?
Dennis: Oh yeah. Roll your damage.
Dennis: Your axe easily bites through his crude leather armor. Kelgan, you literally cleave him in two, and his bloody torso falls a distance from the rest of his body. Rovan, how about you?
Calvin: Let loose an arrow into the other one (Rolls die). Rolled a 20 on the die.
Dennis: Critical threat. Roll to confirm.
Calvin: 16, plus 5 from my attack bonus and my dexterity stat. A hit? (Dennis nods, and Calvin rolls his damage dice). 15, from my triple critical damage and my sneak attack bonus.
Dennis: Your arrow sails right into the guy's forehead. He's down on the ground, dead.
Anne: Something's wrong. That was too easy.
Bob: Aye. The guards at the church of Pelor would be more than a match for these guys.
Dennis: Roll Spot checks (All the players roll dice and tell the DM the results). Ooh, all of you fail. As you guys are milling around, wondering why there aren't more of them and searching for the relic, you fail to see the bandits' blood pooling into an unholy symbol written on the floor. A great winged serpent, made of coagulated blood, rises from the floor. It roars, shaking the old building to its foundations. Elanna, roll a Spellcraft check - since you might recognize this process, you may not be surprised, and can thus take an action.
Anne: (Rolls and succeeds) Whew. I cast Fireball at the monster (Rolls damage).
Dennis: With a low roar, a ball of fire erupts right at the serpent. It obviously didn't like that, and it's stunned for a bit, but now most of the building is on fire, and the fire's spreading.
Calvin: Might be a good idea to get out now. I retreat out the way we came.
Dennis: The door's locked from the outside now!
Calvin: Oh crap.And so it goes. Will the PCs defeat this gruesome monster? Will they get out of the burning church? Who drew that unholy symbol - the bandits or someone even more evil? Will Rovan ever care about anything more than his next score? The players might succeed, they might fail, but they'll have fun doing it.