Salt & Iron (L5R Reskin)
L5R uses a system of ten-sided dice, or d10, for resolution of rolls. This system has the players roll a certain number of dice and keep a number of them (Usually notated as XkY, i.e. 3k2). The usual formula for this is the player rolls dice equal to their Skill plus Trait and keep the Trait. For every two dice rolled above ten, one extra die is kept, odd dice are added as a +2 bonus to the roll. For every die kept over ten, a +2 bonus is added.
In the chance that a 10 is rolled on a skill check a player is trained in, the die is said to “Explode”. Tens are rerolled and the new roll is added to the 10. For example, Hilka wants to climb a cliff, so she rolls the 5k3 for her Athletics/Strength check. She gets 10, 10, 5, 3, 3. She keeps the two 10s and 5 for a total of 25, but she gets to explode the 10s. On the first one, she rerols and gets a 4, making that die worth 14. On the second, she gets another 10 follwed by a 5, making that die worth 25. Her total is now 14+25+5 or 44.