Roll modifiers are special codes appended to dice expressions (like `d6`, `4d10`, etc.) that change the standard behavior of the roll. Instead of simply summing the results, modifiers can alter which dice are kept or dropped, cause dice to be rerolled or explode, count successes instead of totals, and more. They provide flexibility to represent various game mechanics.
The tavern falls quiet. You spent all week on this villain: the scarred voice, the secret letter, the slow reveal in the final act. Your players have other plans. They have just set fire to the only bridge out of town, the paladin is deep in an argument with a goat, and the rogue has quietly pocketed the letter that was supposed to unravel everything. Somewhere across the river, your villain stands alone in the rain, waiting for an entrance that will never come. The bard leans back, grinning. Four faces turn to you.