Unheroic Samurai is a set of free wargames rules for combat with classical Samurai versus undead horrors.
RAFM offers a set of free wargames rules for skirmishes: Universal Soldier Extreme / Modern Day Heroes
Universal Soldier Extreme is a set of rules for skirmish level miniature gaming using Rafm Miniatures. The focus of the main rules is on the modern era and optional rules are provided to suit any genre ranging from horror, to pulp fiction, to historical combat. The rules focus on the Modern Day Hero’s line as well as the Cthulthu mythos creatures. The inspiration for these figures comes from the traditional H.P. Lovecraft Horror genre as well as modern movies and cinema. These rules are a skirmish level set of rules. This means that each player would command between five and ten miniatures at a time. Although flexible enough to handle many more miniatures it is up to the players to decide how big a game they desire to play. We have found that a game of this level with two players can be finished in one and half to two hours playing time.
44: A Game of Automatic Fear is a free rpg set in a 1950s where a conspiracy is replacing humanity with robots.
Cornell University has an online exhibit with some fantastic images of devils, demons, witches and the like. I really enjoyed browsing the collection and couldn’t help but think how neat it would be see a line of miniatures using these as inspiration.