I'm trying to make a game where you get a specific chance, for example, lets say i did it and i could get something that has a 1 out of 5 chance, or maybe 1 out of 300, i know it's hard to understand, but really just need help.

To make something happen with a 1 in 5 chance:

if <(pick random (1) to (5)) = (1)> then
anything you put here has a 1 in 5 chance to run when the if check runs :: grey
end

for a 1 in 300:

if <(pick random (1) to (300)) = (1)> then
anything you put here has a 1 in 300 chance to run when the if check runs :: grey
end

Hopefully you can see the pattern.

Let me know if any of this doesn't make sense. Also, for future reference this post would be better suited to the Help With Scripts category.