So why D10?

Because it is the only system to do this game justice. I'm sorry, but if you play L5R with the D20 System, you are not playing L5R. You are playing D&D with samurai and shugenja (maybe - the players may all be fighters, rogues, and rangers). If you want to play L5R, you need a system that handles honor and that can kill you with one hit. There is nothing wrong with D20, it just so incredibly doesn't fit the setting. It's kind of like using the rules from Rifts to play a White Wolf game. I've seen the conversions. They are frightening.

Just to illustrate the difference between the two, here are excerpts from two books, one d10, the other d20:

When we first started designing the combat system, we brought on a profesional consultant. His name is Tony Kull... I explained to him the idea of the classic "five second combat round," and asked him how many times he could hit me in five seconds.

Sensei Tony smiled his wicked smile and said, "I only need to hit you once."

John Wick, Legend of the Five Rings: Gamemaster's Pack (2nd version), p. 8

Hida Tamoro [Sam 5/ Hida Defender 7 - Ryu] faces the Iaijutsu Master Kakita Kudako [Sam 5/ Iaijutsu master 7 - Ryu] in an iaijutsu duel...

[Kudako strikes] Her damage is 1d10+5 (her normal damage with a katana) plus 4d6+8. [Her bonuses for "focusing her ki" - Ryu] She rolls 30, bringing Tamoro down to 71 hit points...

[Tamoro strikes] His damage is 1d10+8. He rolls a 13, bringing Kudako to 69 hit points.

James Wyatt, Dungeons & Dragons: Oriental Adventures, p.82

D20 simply does not capture the essence of Legend of the Five Rings. I use it for playing Rifts, but not for L5R.

	So why D10?

I try to follow the Bayushi without being noticed.