Many of them can be re-rolled later once you get more skill points.

It calls these white checks. Specifically they'll unlock again (supposing you failed them) once you level up the skill or stat they're associated to.

You can also find or buy dice that'll unlock some of them.

Others are one and done unless you reload or start a new game.

It calls these red checks. And they're often much more fun than white checks, especially when you fail them.