Chaos Scrolls

Chaos scrolls can fail, and the number of change can also change by 2 and 4.

40% fail
60% success
v
30% increase
30% decrease
v
5.45(repeating)% no effect, and the possibility of being +/- 1, 2, 3, 4 or 5.

So now you have

(approximate numbers)
40% - fail
5.45% - +5
5.45% - +4
5.45% - +3
5.45% - +2
5.45% - +1
5.45% - 0
5.45% - -1
5.45% - -2
5.45% - -3
5.45% - -4
5.45% - -5

So chaos' are kinda like 30% dark scrolls. You have a 30% chance of getting a result you want (getting a + in stat). Some food for thought~