First, let me start you off with some basics: You begin by picking either Horde or Alliance, this is what faction your character is in. The two factions are at war with each other, so you can not speak to another player in a different faction or trade with them or do any stuff that you can do with people of your own faction. You can only kill them... but I wont get into that for now. Anyways, within each faction there are 4 races to choose from (well, 5 if you have the expansion pack, and soon, 6, with Cataclysm coming out in the near future). Alliance has Human, Gnome, Dwarf, and Nightelf, (and Draenei if you have the expansion pack). Horde has Troll, Undead, Orc, and Tauren, (and Bloodelf if you have the expansion pack).
You also pick with class your character is, for example you can be a Hunter, specializing with taming beasts, and utilizing bows and axes, a Warlock, specializing with demonology, and shadow magic, or even a Warrior, who rushes into the heat of the battle with his trusty sword,axe, staff, mace, or what ever you can think of, to tank the boss. (Tanking means holding the attention of a monster while people attack it).
Point is, each class has its unique abilities and skills, and you can not change from one class to another once you start your character (but you can make multiple characters, and with the upcoming Cataclysm expansion pack, you can switch from one race to any one that has the same class available that you are, assuming that you are the same faction).
Once you create your character, you are submersed into a world that is totally unique to the Warcraft Games Series. You level up your character by doing quests or killing monsters (or both). You can level your character to 80, and each new level gets harder and harder to reach, as the amount of experience required to reach the next level is increased...But so are your stats, so you deal more damage, and kill higher level monsters (which give you more exp), more quickly. I guess it's kind of like a self sustained cycle.
You can purchase anything from food (to replenish your health), to armor (to provide better defenses and stats), to leather (to leatherwork into something, assuming you have leatherworking as one of your professions), to of course, weaponry. You can even purchase creatures to ride on, which make traveling alot faster. Once you reach level 30, you can get a "mount" that increased your speed by 60%, then, at level 40, you can get one that increases it by 100%, and then at level 70, you can get a flying mount, which only increases your speed by 60%, but allows you to fly over obstacles that once obscured the pathway for your land mount. If you have enough money (and it's a lot) you can buy a flying mount that goes at 280% of the speed you normally run at, but that is in the air. On land, it can run at 100% faster than you normally can.
You can choose 2 professions, anything from mining various ores from the deposits in the ground, to cooking up potions and herbs. There are about 15 professions from which you can choose from, and you can unlearn any that you know at any given time. Your professions will most likely be the source from which the majority of you money will come from.
You can also auction items off on the in-game auction house, and purchase others' auctions.
Anyways, the game itself costs $20 for the original, $30 for the first expansion, and $40 for the 2nd expansion (you don't have to get all three if you don't want to, you can play the game with only the actual original $20 copy, but a lot of cool new and exciting content is in the expansions). After buying the game, you have to pay around $15 each month, ($12 a month if you decide to pay for the entire year in advance), so it's a bit expensive, but take it from me - this is by far the most tun investment I have ever made, and I am sure that you will agree if you decide to play it.
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