Shoddy Battle is a 'battle simulator'. It's a program that runs on your computer and lets you play Pokemon battles against other people. (It has a Find Match function, similar to PBR random-WiFi, so you don't need to know people to play against them). You can create any legal Pokemon in the 'Team Builder', so you don't have to worry about breeding and training and whatnot but can instead focus on making a great team and battling with it. It takes a bit of getting used to, as the visuals are a bit spartan, with no move animations. Many people's primary focus is on Shoddy, but it can also be used to test teams before you put in the effort of making them on the cartridge. (Though bear in mind that the Rotom Appliances are very common on Shoddy, but cannot be used on WiFi play, and there are metagame differences too.)