Don't be fooled by counterfeit imitations when completing your game library.
Bootleg games are illegal copies of legitimate games. There are four quick and easy ways to spot if a Nintendo DS cartridge is a bootleg. If suspicious, check multiple items – not all bootlegs will have the same flaws.
#1 – Cartridge won't boot in a Nintendo DSi unit:
As the newest version of the DS system on the market, the Nintendo DSi includes a newer version of the operating system from the manufacturer that does a better job at detecting bootleg software and rejecting it with an error message. After launching the game, you'll see the message below displayed on the bottom screen.
Power down the system, remove the cartridge and re-insert it. Power the system back on and try to launch the game. If you receive this error again, it's very likely you have a bootleg game.
#2 – Cartridge Construction is of low quality:
Two things you can quickly check without having a Nintendo DSi handy is the quality of the cartridge's construction. First, with any Nintendo DS cartridge you'll notice a seam down the middle of the side. If you tug on this with a fingernail, the cartridge should not separate at all. If it does, you've got a bootleg.
Second, look at the back of the cartridge. Here, you see a bootleg cartridge on the left and a real cartridge on the right. Inside the Nintendo Racetrack logo, you'll notice that outlined in blue, the real cartridge has the registered trademark logo ® after the word "Nintendo". This is missing from the bootleg. Also, above the gold contact points, there are white letters and numbers. While the letters in this picture say "Nintendo", not all cartridges will – but all legitimate cartridges will have white letters above these gold contact points.
#3 - Matching the Serial Numbers:
Each published title has a serial number unique to itself. This serial number can be found on the front of the cartridge and on the back of the game case, next to the UPC. On the cartridge, you''ll find the serial number in the format of NTR-XXXX-YYY, where XXXX is the unique serial number for that game, and YYY represents the region, such as USA.
On the back of the game case, you''ll find the serial number again, in the format of NTR-P-XXXX, again where XXXX is the unique serial number. These two serial numbers will always match on a legitimate copy of the game. Also, compare this serial number to the string of letters printed in black on the back of the cartridge. The first four letters on the back will always match this serial number as well.
#4 – The Case of the Odd Case:
There are three types of DS Game Cases. The standard US case is black and has a slot for holding Game Boy Advance games that is solid. Newer "eco-friendly" DS cases have no GBA slot and feature a cut-out recycling symbol behind the manual. The Japanese case is black and has a slot for holding Game Boy Advance games that is in three pieces. The European case is clear and thicker, to accommodate game manuals in multiple languages. Games sold in the US are NEVER sold in the European style cases and rarely ever sold in the Japanese style cases. While there are a few exceptions to the Japanese cases, if you spot a US game in a Japanese case, it should draw your attention to look at the game itself more closely.
In the photo on the left, you'll see a European-style DS case on the left side and a US-style DS case on the right side. In the photo on the right, you'll see a Japanese-style DS case on the left side and a US-style DS case on the right side.
You can find further information about Nintendo's Anti-Piracy program on the official website. There are tips on how to identify counterfeit software for all consoles, not just the DS family, and photos for each category too.