Written by several authors (me included) the pocked sized USEME series of wargaming rules are really easy to learn and most are solo play too. Sci-fi, Fantasy, WW2, Modern, Wild West and ACW, Zombies, Cyberpunk, Eldritch Horror and more. There are also many free downloads and scenarios. Print and Digital Download versions too. Excellent for kids, adult and those wanting a twenty minute game with their miniatures.