Spotting fake DS games

[Strider]

What to look for?
I've just received a copy of Contra 4 from CEX and it won't work on my DSI XL. It works fine on my DS Lite, but I get an error message. Is it a fake or region locked? I tried my US copy of Magnetica and that's fine.

[importaku]

What region is the XL & contra 4?

The only time ds games seem to be region locked on a dsi is if they have dsi features on them like using the camera. I can't imagine contra 4 having any dsi camera features so it's quite likely your copy might be a bootleg. If there was dsi features they would be mentioned on the back of the box. Thats why dodgy copies on ebay say incompatible with dsi in the auction text as nintendo has better ways of detecting fake carts on dsi as it uses a new os where the old ds will boot pretty much anything either real or fake.

Look on the back of the cart, there should be a printed serial number in black ink on the plastic just below the nintendo logo, all carts should have that.

[Strider]

it's US Contra and A UK DSiXL. There is a printed serial number in black ink on the plastic below the logo.

[speedlolita]

Take a picture of the cart.

[Mayhem]

Most of the pirates are US versions, so that is a warning bell already. I have a genuine US Contra 4 here; the cart label just has Contra 4 on it with the usual other logos on it, and the instruction manual has 30 pages, colour cover but all inside is b/w.