(photo by Benimoto)
Think of Dungeons and Dragons like one of those Choose Your Own Adventure books, except the book is blank and the Dungeon Master fills it out himself and is reading it to you. Then you (and your characters) try to navigate through the book without getting yourself killed.
The Dungeon Master is the person who creates the world and makes all the big decisions. Everybody else creates a character.
The Dungeon Master begins weaving the story, explaining to the characters where they are and what their goal is- a good DM will do this with lots of enthusiasm and flair!
The characters then make their own choices based on their religion, their background, and their skills. For example- a Human who hates Orcs would never say, “I love Orcs! Let’s be friends with this Orc!” Instead, they’d be more likely to say, “Kill the Orc!! I hate that guy!”
The story almost always involves a particular quest they’re trying to complete, or bad guy they’re trying to stop. In a long campaign there are probably multiple interleaving storylines that pop up over and over again, just like in a long-running TV series.
Apart from the storytelling and role playing, there is combat. Whenever you come across a bad guy on your journey, the DM has created a character for him and will control him. If you decide to attack the bad guy, you must roll the dice a few times.
The first time is to figure out who gets to attack first- this can be a big factor in who wins a battle.
The second dice roll is to determine whether you hit him or not- if you roll below a certain number (which the DM knows but you do not), then you miss. If you roll a 1, that is a critical failure and commonly ends with you breaking your weapon or hurting yourself. Conversely, if you roll a 20, that’s a critical hit and you get to do extra damage!
Damage is the third roll. That’s how you figure out how much health he loses when you attack him.
Now, battles aren’t the only place you get to show off your talents and skills! Often, throughout the story, you will have to do a skill check. These are used to figure out if you can complete a certain task and how well you do it.
For example- you need to lie to a bartender so he doesn’t know you’re looking for the treasure! If you roll a high speech skill check, you might say- “We’re not searching for treasure- we’re just in town to sell our wares and buy new armor.” If you roll low, you might say- “We… uh… treasure? I never met the guy! Ahaha… we’re definitely not treasure hunting. Nope. Not us. I don’t even know what treasure is!”
The "goal" of the game depends on the story that is being told by the DM — it may just be to kill as many monsters as you can, or it might be to destabilize an evil government and restore the rightful ruler, or it might even be to prevent the destruction of the world. A good story can be as small or as big in scale and scope as the DM wants it to be.