In any role-playing game or RPG you are playing as a fictional character, normally it's in a fantasy world, you will have normally pretty much full control of your character. An MMORPG is distinguished from other RPG's by how many people are playing the game.

If you don't think MMORPG's are popular, just bare in mind that revenues in 2005 were over half a billion dollars, and in 2006 the Western world only, revenues were over one billion. And the revenue's keep rising every year with new games hitting the market.

MMORPG's have themes most of the time it's going to be a fantasy theme, comparable to Dungeons & Dragons. However there are several other themes that you will be able to find, such as science fiction, sword and sorcery, and crime fiction. There are some more obscure themes offered like American comic books, or even the occult. You normally have to take on quests to earn or get items that will help you out in the game to progress further. Plus there are monsters who you continually battle, sometimes getting loot after winning.

When your playing an MMORPG normally your overall goal is to progress your character up to high levels, thus receiving more powers or other goals. You do this by earning experience points, which will increase your level once you have enough. The way this will normally take place is by fighting monsters, or even completeing quests. You can do both of these either by yourself or with a group.

When you get in a group you can take on higher level monsters, which will get your experience up faster. If you have a high level paladian (healer) who will come by your group and heal you can even do power leveling. This is a super quick way of getting those levels you need to open up more opportunities for your character.

Yes MMORPG's are very addictive if your not careful they may take over your whole world, causing a change in your work schedule just to play. However you just have to walk away if this starts to happen.

Another great thing about MMORPG's is the social interaction. Remember there are possibly people from all over the world on the game with you. What is also cool though, you might meet someone to be a lifelong friend who can help you out in times of need. Most MMORPG's have clans or groups that you can join and these gives you a nice group of friends to communicate with when you are playing.

Some people to get too involved in the game and start thinking of it as their real life. Or start having real relationships with others online, acting like they are married and all. It's really wild to think of a game sucking in someone that much, but it can happen. Just as stated before be careful and don't get carried away, yeah it's only a game, but a really cool game.