For this week, I've written up an Ars Magica die roller. Ars Magica's dice conventions are unique, using three different types of rolls, all of which are based on ten-sided dice:

• Simple Roll: This is just your basic d10 roll with 0 read as 10.
• Quality Roll: In a quality roll, 2-10 are read normally, but a roll of 1 means to re-roll, doubling the result. Further rolls of 1 will repeatedly double the final result, allowing for arbitrarily high rolls. For example, rolling 1-1-1-7 is read as 56 (7, doubled three times).
• Stress Roll: Stress rolls are basically like quality rolls, but with the potential for very bad results as well as very good. A stress die is rolled just like a quality die, except that, if the initial roll is a 0, the total of the roll is 0, regardless of any modifiers, and the die is rerolled to determine whether you have botched your attempted action. Under poor circumstances, additional botch dice may be called for. If any botch die comes up 0, something bad has happened in addition to having failed. If multiple botch dice are rolled and more than one 0 is rolled, each 0 makes the result even worse.