when using mastercard as a paying option you have to enter your number in the format:
aaaa bbbb cccc dddd
and then your security code. the security code is the 3digits on the back of your card:
zzz
but unfortunately gog.com marks the security code as invalid if you only type in the 3digits.
you have to use:
ddddzzz
as the sec code with dddd being the last 4digits of your cc number.
i happen to shop often online and this is not handled this way by other webshops, maybe you wanna correct that to avoid confusion.
- then not being able to process the order is another thing, I assume you have problems with mastercard authorization ?
thx, toni

I'll try this ddddzzz thing. I've had a ticket in for the last day trying to figure out why it keeps rejecting my security code. I wonder if it's doing this for everyone or just some. It's doing it to me with a Visa.

I don't have Mastercard, but I used Visa and I didn't have a problem. I guess it's just luck?

thanks for the reply, i already contacted them. just wanted to give others a heads up that this can happen.

I'm having the same problem with my Visa. I can't even add in the extra digits to try the suggested solution.