Battle of la Drang is a set of free wargames rules for battles between the US 7th Cavalry and Vietcong forces. The battle of the title was the basis for the book and movie, “We Were Soldiers.”
Full Metal Potato Jacket is a set of free wargames rules small unit actions in Vietnam.
Grunts, Leathernecks and Charlie is a set of free wargames rules set in the Vietnam War. The author writes:
Players who are interested in a FUN and FAST Vietnam game system can consider these rules a flexible framework for use. I designed these rules to be used by both beginners and veteran players. Play can be quick and easy OR made more realistic and slower by adding advanced options. If you do not trust your opponents, then this is not the right rules’ set to use. It will assist any player who has an interesting scenario to run at a convention or at a local shop. The Combat systems reflect volume of fire into a specific area combined with the maneuvers of combat units.
Andy Watkins offers a set of relatively simple Vietnam War rules.
The Black Dog of Doom offers a set of free wargames rules for Vietnam Skirmishes.
The author writes:
This is a set of wargame rules for playing a middling size skirmish set in the American/Vietnam war. The rules were written for use with 20mm metal minis and have been used in that role a number of times.
As well as the figures and terrain, you will also need to supply some standard dice, a measuring stick, lots of tiddley winks and some crunched up balls of paper!
The rules feature the use of supressing fire which will pin all but the bravest of warriors. In game terms, supressing fire reduces the ability of the supressed to interfere with your plans.
Also included are some rules for handling vehicles and artillery fire, although these features are not expected be the focus of the game. In play each player will easily be able to handle 20-30 figures.