I am not familiar with 4e sheet (as in if its built in, I have no idea) at all but what you want is Rerolling Dice So if you had 1d8r<2, that with reroll any 2 and 1 until its at least a 3. This seems to match what I read brutal as. Now for entering it on a sheet, having a quick glance at it is seems to be more make you own style of rolling. So something like the following of the basic example <a href="https://i.imgur.com/5mKKEzL.png" rel="nofollow">https://i.imgur.com/5mKKEzL.png</a> So wherever your damage dice is, as long as you use the format r<x right after the die size (1d10r<2) then it should work from what I can tell at a glance of what 4e brutal is and their character sheet on how to enter.