Core/Functions: Chance Roll script update. After some hard thinking and some testing, both codes in issue https://github.com/mangosvb/serverZero/issues/28 work as they should. This code update seems more sensible to use, then the other one.

After comparing the Chance Roll on TrinityCore & Mangos, the code converted from C++ to VB.Net follows the same path, which ending the Code Discrepancy.