I sometimes think that it's a lot like D&D 'roll with advantage/disadvantage'.  (For non gamers, that's 'instead of rolling 1 20-sided die (a d20), roll 2 and take the higher/lower'). You can still roll a 1 on '2d20, take the higher' and roll a 20 on '2d20, take the lower', but it's a lot harder.