2020-04-22 What about opposed 2d6 probabilities?

I was wondering: if we roll opposed 2d6 rolls, what are the chances of beating your opponent? It must be around 50% but somewhat less, because both rolling a seven – the most likely result – is undecided, that is: you didn’t beat your opponent.

And what about your chances when you get a +1 and your opponent doesn’t? I started wondering but I also didn’t want to dive back into the introduction to statistics I must have in my bookshelf somewhere. And I also didn’t want to look it up on AnyDice.

I started thinking: with just 2d6, it should be possible to explain it all using tables and counting... and I did it! I wrote a little three page PDF about it: Understanding 2d6 Math.

Enjoy! 🙂



I’d also consider loop N over {0..11}{output 2d6-2d6<N named "+[N]"}

edkalrio 2020-04-23 12:19 UTC

Oh, very cool! Thank’s a lot.

– Alex Schroeder 2020-04-23 18:07 UTC

Ynas Midgard’s review of Best Left Buried makes me think I should have a look at its mechanics...

– Alex Schroeder 2020-04-27 08:17 UTC

It always struck me as super weird that Starblazer and Anglerre didn’t use 2d6 vs 7 instead of the cockamamie system it went with, which has the exact same probabilities as 2d6 vs 7 in every single way.

Sandra 2020-09-14 21:44 UTC

Ah, those were the 1d6-1d6 systems, right? A sort of Fate dice alternative. I think they wanted to keep the Fate ladder and that’s why they didn’t want to start using a ladder centred around 7 instead of 0... But I’m just guessing.

– Alex 2020-09-15 08:00 UTC

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