You need to first establish that the type was chosen intentionally before asking why it was intentionally chosen. Otherwise the question is ill-formed. It look

You need to first establish that the type was chosen intentionally before asking why it was intentionally chosen. Otherwise the question is ill-formed. It looks like they are using PHP/MySQL/Javascript/Flash, with only MySQL having any explicit types. Even so, an error is often preferable to overflow, which is usually undefined behavior and could lead to a duplicate primary key anyways if it wraps to the first game. A better question is "why 32-bit over 64-bit", but the site dates back to 2005 where that was the norm and the question has the same issues.