Great! So you may give it a whirl!
Dungeons and Dragons (D&D) is a fantasy-based role play game set in the middle ages. This is era people use spells, swords and mythical creatures roamed the landscape. Treasure was to be found, recovering stolen artifacts or helping out the village people. The game itself is very social and can be seen as a cheap and alternative way of entertainment instead of the mainstream way of spending money at the cinema or having a meal out.
There are two categories of people that are required to play Dungeons and Dragons, there are the players and Dungeon Masters. These two elements are explained below.
The role of a player is to create a character. The player creates the character by generally choosing a class (explained below), gender, physical characteristics and a personality. These elements create a whole character which interacts with the world that the Dungeon Master creates. The player must role play (or act) that character. It can be seen as an actor portraying his or her character to an audience.
There is also the Dungeon Master role. The Dungeon Master (DM) or Game Master (GM) creates a story and it is the Dungeon Master's job to guide the players through the story. I use the word guide loosely, because the players sometimes dictate what their character is doing and the Dungeon Master has to adapt to what the player is doing and modify the story slightly. This means there are limitless adventures to explore with Dungeons and Dragons and the story is very open ended i.e. anything can happen. Just think of it as this way: The Dungeon Master may set up an adventure where the players have to save a town from a raid of bandits. However, the players decide to spend the days and night getting drunk in the tavern...The DM has to adapt to this and role play accordingly...only to continue the story and find half the town destroyed instead of being saved (as originally proposed by the DM). If you enjoy story writing and telling a story rather than being in a story, then be a DM. However, you firstly have to understand how it works as a player.
As stated before, there are several "hidden" mechanics in Dungeons and Dragons that people fail to see on the surface. One mechanic is the "class system". A class in Dungeons and Dragons is the character you play which have a unique set of abilities. Each class is different, with different abilities and therefore played differently. Generally, the player can choose between two categories of classes...either a spell caster (Someone who uses spells to heal, damage and hinder someone) or a weapon specialist (someone who uses weapons such as swords, bows and axes to eliminate their enemies). Generally, spell casters are seen as the supportive role, who support the weapon specialists.
Examples of spell casters include: Wizard/Sorcerer (Use magic to damage or hinder an enemy), Cleric (Uses magic to heal open wounds or mend broken bones) and a Bard (someone who uses music to make allies temporarily stronger, with the use of a mixture of healing and sorcery).
Examples of weapon specialists: Fighter (can use all weapons), Paladin (uses healing magic and can use melee weapons) and a Ranger (mainly uses bows and can dual-wield weapons to attack).
Another hidden mechanics basically reflects how a character develops. Dungeons and Dragons have incorporated a "leveling system". A level represents how strong your character is, the higher the level the stronger the character. How this works is a player, who controls a character, will expose their character to experiences. These experiences include taking part in combat, talking to people around a local town to try and gather some information and solving puzzles, just to name a few. In the game, the character is given "experience points" as a reward. You collect these points and once you accumulate enough you "Level up". Upon "Level up" the character becomes stronger and you gain points to spend into skills and increase your attributes. Your character has become better and more developed. This accumulates over the characters life span and are able to overcome tougher challenges. Just like in real life, the more time (or experience) you spend working out, you become physically stronger so you find the lighter weights easier to lift compared to how difficult you found it at the beginning. Different people find different aspects of Dungeons and Dragons addictive, the leveling up system I find particularly enjoyable.
Don't worry if none of this makes sense to you! A good way to really understand Dungeons and Dragons is to throw yourself in there as a player first of all. One method is watching a game take place...but you truly don't understand what is happening most of the time and can seem boring. However, if you want to play a few games alone, check out the computer games section. If you have a group of friends who want to try it out, I recommend going for the board games which guides you through your first steps of understanding. If you don't have any friends who are interested in this stuff then head over to http://www.meetup.com/ and find a group near you and get involved. You could either be a player or be an assistant DM to learn the ropes of being a dungeon master. However, if you want to dive into the real thing straight away, have a look at the manuals that are necessary to start playing DnD.