They've actually created two huge ways to reduce the chance of even needing to make a return: their demo nights (try out new games) and rather extensive game library (again, allows you to try before you buy). Utilizing those two programs is meant to help make that purchase, the right one. So rather, think of reasons why you would want to return something, then see if they have a program to help you mitigate those reasons.
Yes there is one. You can return unopened games with receipt for store credit.
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