Selecting a feat multiple times

[spamandtuna]

The D&D rules explicitly say "You can take each feat only once, unless the feat’s description says otherwise."

Does a similar line exist in the SG rules?  There are a number of feats that do say you can select it multiple times (often with some additional condition).  However, there's other feats that I would expect to allow multiple and seemingly don't: Ability Score Increase, for example.

Furthermore, how does this stack with class features?  If I'm a medic with the First Response class feature, does that prevent me from taking the First Response feat?  If so, where is that rule written?

[1001100x02]

Occum's Razor applies: when in doubt, go with the simplest answer. The game is based on 5E so unless the game specifically states a difference exists, assume standard 5E rules apply.

(similarly, Absence of Evidence is not Evidence of Absence)

[spamandtuna]

Sure… but I still like my rules to be explicit.

What does that mean for the ASI feat, though?  Is it intentionally selectable only once?

[TForbes]

To answer some of your specific questions, I think "Ability Score Increase" is able to be taken multiple times, the limit imposed is that none of the abilities can go beyond 20.

For the other question... my understanding is that Class features are simply "free access to the associated feat" so if you get the feat from your class, and it is not repeatable, you can't separately purchase that feat.