The prolific Tyneside Wargames Club has produced a set of free wargames rules for early 19th Century Skirmishes.
19th Century
WRG 1750 – 1850
Dating to 1972, the Wargames Research Group’s 1750 – 1850 are primarily intended for the Napoleonic Wars. By modern standards they’re a bit dated, but my recollection is that they are fun.
Edwardian Splendor 54mm Rules
Edwardian Splendor is a set of free wargames rules for playing games with 54mm figures.
Sending MacDuff To The Front Rules
Ross MacFarlane offers a set of set of free wargames rules for the late 19th/ early 20th centuries called Sending MacDuff to the Front.