Well, mechanically, L5R is a "Roll / Keep" system with "exploding dice". Roll a bunch of d10s, keep some of them and add them together to get your total (modifiers can alter the roll, the keep, or even the final total).
To resolve an action, such as striking a target with your katana, you'd take your skill in it plus your trait add them together and get the total number of d10s you'd roll.
Let's say your Katana skill Kenjutsu isa 3 and your trait (agility) is 2 that would be 5d10 (2+3=5) to ROLL for your attack. After rolling you get 2, 6, 8, 6, 10... you'd automatically re-roll the 10, and add the new number, of say a 3. Which would make the numbers look like this now: 2, 6, 8, 6, 13 and because your trait of agility is 2, you get to KEEP the two highes…