easy/free mass combat system?

[BastionLightbringer]

I remember reading on a board somewhere about a system for combat between armies that was pretty simple, but now I cant find it. You added plusses & minuses for different modifiers like archers, higher ground, cavalry, etc then added them to a d20 roll and compared the rolls to a result chart.
Does anyone know where i can find this or find another easy system. Need it for a one time altercation.

thnks

 

[GMSkarka]

I don't think this is the one you were speaking of, but Mongoose has offerred a D20 mass combat system (which was cut out of the final release of the CONAN rulebook) as a free PDF on their site:

Click here to download (849k)