Minecraft generates a new world every time you start a new game. This adds tremendous replay value, but also means you can easily get screwed by starting a game that's in a world that just happens to suck. No more! The 1.3 Beta update released in February allows you to both create as many world as you want AND do many more things with seeds than before. Every world has a seed, and now you can save the seed from any world you make to reuse later and load millions of seeds preloaded into the game that makes awesome worlds. Now, you can play in an awesome world that suits your gameplay style any time you want to. Want a world with tons of Iron? You got it. Want to build your fortress inside a volcano? There's a world that will start you next to one. The fun is really limitless.