I got an interesting question on Reddit the other day:
Why use opposed 2d6?
Firstly, I think I like rolling dice as a referee so designs where the referee rolls no dice weren’t appealing, e.g. Dungeon World. Second, in systems where the referee sets difficulty levels I feel continuously stressed out by having to determine all these things, maybe even defend my assessment against players, e.g. Traveller. When I saw the opposed roll in the Blackmoor documentary, I saw that rolling for circumstances was best: I can always interpret the oracle of the dice.
That is, instead of wondering “how difficult is this computer to hack, exactly?” I can simply decide “it’s probably a bit harder than normal” and roll 2d6+1, and then we’ll all know whether this computer has decent ICE installed...