Rules

[pws]

I couldn't see Ronin for solo play, as the melee mechanics require one to try to outwit his opponent on choosing whether to use a defensive or offensive strategy - hard to do playing left hand against right.  Good game system though, and I strongly recommend it for use against an opponent.

I agree although I prefer Daisho rules instead of Ronin, but solo gaming with those rulesets is very limited as they need 2+ players.

You could try something different, if I may suggest to adapt Sellswords-and-Spellslingers in a samurai set-up as they did with  Conan Beyond the Black River . SS&SS has been created minded for SOLO/COOP , try it "fantasy" or Conan a couple of times and maybe it could be your game, as all other Ganesha games it's not difficult to create your own heros and NPC.

[Patrice]

There is a Sengoku extension for "Argad", more intended for RPG-minded small skirmish but which has sometimes been adapted for ...quite big skirmishes. 

[Maniac]

Ronin is a great system for small group play.  The ninja assassination scenario is probably the most adaptable for solo play. 

That said, I'll also mention Fistful of Lead.  They recently released a Fistful of of Lead: Might and Melee, which is perfect for small unit battles as well.  Slightly different mechanics, but you can translate most of the Ronin abilities and characters pretty well.  I also like the card mechanic for activation.  I'm certainly looking at converting my Ronin forces over to FFoL.

Plus, as noted, you can play Bigger Battles, which just scales the system up.