Add an array with a width of 30 and a variable number
for start index 0, endindex 29
number = int(random(loopindex))
Set Array.At(loopindex) to number
far greater chance of filling the array with lower numbers, and 30 may come up only once, probably not at all.
Then you would just pick a random number from this array
Probably quicker than advanced random plugin which I have never needed, but depending on your needs which are not 100% clear you may be better off with the plugin
a single action like choose (1,2,3,1,2,1,2,1,1,2) can do the job too In that example 1 has a 50% chance of coming up, 3 has only 10% chance