Games Workshop’s Lord of the Rings rules set has turned out to be very flexible, spawning several commercial sets, such as Legends of the Old West and Legends of the High Seas and innumerable fan variants. Legends of the Feudal Times is a set of feudal skirmish rules originally published in the French language magazine Vae Victis. The English translation is here.
Lord of the Rings Variants
Wars of the Roses Supplement for LoTR Strategy Battle Game
Here’s a Wars of the Roses supplement for the Lord of the Rings Strategy Battle Game. The original link has died. I’ve attached a copy below.
Napoleonic Strategy Battle Game
The Lord of the Rings Rules variants Yahoo Group has a set for Napoleonics.
Isildur’s Bane Solitare LotR Battle Game Rules
Isildur’s Bane is a set of free wargames rules for playing solo games of the Lord of the Rings Battle Game.
Legends of Old Mars LotR LotOW Variant
Legends of Old Mars is a Edgar Rice Burroughs’ Barsoom variant of Games Workshop’s Lord of the Rings / Legends of the Old West game. I think that system is perfect for playing games involving John Carter, Tars Tarkas and the other denizens of Burrough’s Barsoom.