And it is better if instruments are available. For example, in oWoD (that is basically WoD now) it is a good idea NOT to name the difficulty of a die roll (DC, basically) and the amount of successes needed. The GM just tells you what happened, not even "you succeeded" or "you failed", so what seems to be a success can actually be a dramatic failure.
The next step is not even showing dice to players, all rolls are made by the GM. Works perfectly, allowing to sometimes change the roll result to whatever is needed for the current story.