You buy ds or 3ds games and then put them in your 3ds.
No, 3DS games can only be played on the 3DS.
Yes, it does. There are Nintendo 3DS games that are exclusively for the 3DS family.
Yes, the 3DS has games specifically designed for the system on cartridges and available through the eShop.
No. The 3DS is region locked, EU games will not work on a US 3DS.
No, only a 3DS can play 3DS games.
No, 3DS games only work on the 3DS and 3DS XL as well as the 2DS
No, dsi games work in a 3ds, wont appear 3d though, but the dsi does not have the ability to play 3ds games.
Yes, the Nintendo 3DS can play DS games as well as 3DS games in 2D
No, you can play regular DS games on the 3DS. However the 3D games can only be played on the 3DS :)
Nintendo 3DS games are in the form of a cartridge that is similar in size and shape to Nintendo 3DS games.
You can play Nintendo DS and DSi games on the 3ds, but the 3ds doesn't have a slot on the bottom for Gameboy games.