[[Image:Quest-cow-recipe.jpg|frame]]You must finish the game first (Kill Diablo in D2, Kill Baal in D2X), and then go back to Act One on the same difficulty level, and execute the recipe, Wirt's Leg + a Town Portal tome, while your character is standing in the Rogue Encampment. You do not need to carry around Wirt's Leg forever; just go back to Tristram any time and click his corpse to get a new one.
[[Image:Quest-cow-portal.jpg|framethumb|200px|right]]Prior to v1.02 you could go to the Cow Level as many times as you wanted to, so if you really love it in single player, you could uninstall, reinstall Diablo II, and then play do the Cow Level with your open or single player characters as many times as you want to, as long as you don't upgrade past v1.01. In the current version, you may repeat the Cow Level as often as you like, providing you do not receive quest credit for killing the cow king.
As for the Cow Level itself, it's about what you would expect. Cows and more cows, called [[Hell Bovine]]s, appear in huge, almost never-ending herds. By far the most tightly-packed monsters you see anywhere in the game can be found in the Cow Level. Every cow looks the same, there is no variation in coloration or weaponry at all. They all have massive polearms, and do quite heavy damage when they strike you with their very fast attacks.
The level is all on the surface, there aren't any sub levels or dungeon or cave areas, but there is a main wooden stockade sort of area, with walls just like those in the Rogue Encampment. It is square in shape, with openings on all sides, and a number of dead Rogues lying around, and others tied to stakes, as you often see them in Act One. It's not a real good place to fight in, since the approaching cows can easily fill every exit and you do not want to be cornered by them. Being cornered or too surrounded will get you scenes like this, and as you can imagine, body-retrieval can be a challenge.
[[Image:Quest-cow-king.jpg|frame]]Somewhere inside or just outside of the "fort" as it's called, you'll find the Cow King. He is always Lightning Enchanted, and should be avoided if you wish to retain the ability to open the portal to the level.
=Multiple Visits=