The legality of using VisualBoyAdvance (VBA) or any other emulator depends on how you use it. Emulators themselves are legal, but it is illegal to use them to play games that you do not own or have not obtained through legal means. In other words, if you have legally purchased a copy of a Game Boy Advance (GBA) game, it is generally legal to use an emulator like VBA to play that game on your computer. It's important to note that while emulators themselves are legal, the act of downloading or distributing copyrighted games without permission is illegal and can result in legal consequences. Therefore, you should only use VBA to play GBA games that you own or that are legally available for download. It's also worth noting that the legality of emulators can vary by country and region, so it's important to research the laws in your specific location before using an emulator.