One of the ironies of Dungeons & Dragons is that it was created by people who were into war games like Risk or Axis and Allies, which simulate battles carried out by opposing sides [source: Kushner]. In these games, there are clear winners and losers.
This is not the case in D&D, where the closest a player can come to losing is for his or her character to die. Even then, the player can just create a new character and rejoin the game – the DM will find a way to introduce a new character to the surviving party. Since characters can go on limitless campaigns that may last for hours or months (depending on the breadth of the adventure), the goal of Dungeons & Dragons – beyond just enjoying the story and playing a part in it – is to keep your characters alive and grow their abilities until they're more powerful and better at what they do.
This is done through accumulating experience points (XP) in the game. Every monster slayed and every coin or gem in a captured treasure has an experience point value attached. For killing the rare Minotaur, a difficult adversary indeed, a character is handsomely rewarded with 275 XP. Slaying lesser, more commonly encountered monsters, like a giant centipede or a skeleton, may generate only 10 or 20 XP for a character. On the other hand, treasure tends to grant characters far more XP. Gold coins, for example, offer a 1:1 ratio for experience points, and they're usually found in large amounts in campaigns. Having treasure offer more experience points than killing was a deliberate decision by the game's creators, who wanted players to use their wits to get out of sticky spots [source: Mentzer]. (In other editions, you may get XP for other acts as well, or just based on the DM's sense of your overall contribution.)
With experience points, characters evolve as they enter new levels (all the way up to 36 for human characters in Basic D&D) [source: Mentzer]. Each new level makes them more powerful and more advanced. Clerics and magic-users can learn new spells, for example. Fighters' blows become more deadly; thieves become more adept at picking locks. Even more important, players come to understand their characters and the world more and more, making the game even more enjoyable.
So, you get it: You know who you are and what you're doing. But as a first-time player, how do you do it better? We'll look at that next.