The dice are not your friend

 The dice only exist to give players a chance to fail at something. The dice do not allow you to do things, you do that yourself when you declare your action. Rolling dice only gives a chance of hindering the players, not helping.

D&D is at its core, a dice game in which you declare your action and then roll dice to see if you fail.  If you don't, then you continue onward to gain power and glory.