This article is about the wargame Chainmail. For the armor, see Mail.
One of the earliest mass market wargames.
The rules were published in 1971 by TSR and were based on other, historical wargames. Chainmail, however, had a fantasy bent; artillery was replaced with magic (to the same effect), medics became magical healers, and so forth. Chainmail also included rules for dragons and other fantasy creatures. The game was immensely popular (though niche) and very shortly evolved into Dungeons and Dragons. In fact, the original D&D game recommended that you have a copy of Chainmail to play (though it did come with a d20 attack matrix that become standard and eventually converted into THAC0).
Around the time of 3rd edition, WoTC revived the name as a new D&D-based minatures wargame, creating the Sundered Empire setting to set the battles in as a result of 3e's core setting being basically Greyhawk in disguise. Sadly, this new version of Chainmail didn't last very long.