Yeah that'll get you rerollings 1s and 2s. But it'll also keep re-rolling them, as you can see here: (also wow, fantastic dice rolls!) I tried adding `ro<2` but it still appeared to be re-rolling all 1s and 2s, so it might be a little tricky. Looking through the dice reference Kraynic linked, it should work, but it doesn't appear to function as intended: I checked with 5d10ro<9 and the function allows as many rerolls as initial dice thrown: so for your 3d6 it will allow up to 3 rerolls and no more, which kind of works but it's also lazy and wrong. You may be better served by manually re-rolling.