You either need the game cartridges or you install the games in .cia form to your 3DS's SD card (not the Gateway card). I would suggest getting a larger SD card.Thanks! Another question: One major reason why I didn't want to swtich over to Luma is because I think i read that you are supposed to put your games in your SD card, instead of a microsd gamecart like red gateway? This is so because I only have a very small 4gb SD card and I spent a good sum buying a large microSD for my red gateway when it first came out. Is there any way to use the microsd to play games on Luma?