I can see why the 1d8+1 rolls look confusing, but it's actually working as intended. Roll20 dice expressions don't really have a way of supporting CPR-style crits and fumbles, so here's what the sheet is doing every time it has to roll a d10: 1. It rolls 1d10 to check if the roll is a crit (10) or fumble (1). 2. If it's a crit, it rolls 10+1d10. 3. If it's a fumble, it rolls 1-1d10. 4. If neither a crit nor fumble, it has to generate a number between 2 and 9, so 1d8+1. This is the only way I could find to make crits and fumbles automatic. If anyone knows how to make a Roll20 dice expression that can make crits and fumbles happen more simply, I'd love to hear about it. To attack, you just roll either the Marksmanship or Melee Weapon skill, as appropriate. If you hit, you roll damage. I'll make this more seamless in a future version of the sheet.