It's not about the probability of hitting a specific number, which is indeed infinitely small if you deal with real numbers of infinite precision.

I wasn't claiming that my example was an explanation for this specific instance. Only that the chance of an event occurring with probability 1 does not mean that the event will occur which is contrary to what people in this thread seemed to believe.

If your probability is 1, the condition is always true. Always. If your probability is 0 it is never true.

This is true only if that's how it is done in the software, I am not aware of what RNG algorithm XCom uses or what comparisons are done to determine hit chance and my example was not meant to be an explanation of the mechanics of Xcom. Only to correct the assumption that 100% probability implies certainty of outcome.

An event occurring with probability of 1 is almost surely going to occur. It is not always going to occur. Likewise, an event with probability of 0 can still occur.

Probability of 1 is only a guarantee in a finite sample space.