Ravenfeast is a set of skirmish rules for the Viking Age. It is freely available as a 44 pages PDF booklet. The rules themselves only span 6 pages, the rest covers the historical context, wargaming as a hobby, miniature painting and terrain crafting.
Perhaps the best introduction to this game is the Capturing Alfred video the Little Wars TV people put up. It reconstitutes two episodes of Bernard Cornwell's Sharpe, err, The Last Kingdom where King Alfred is surprised by Dane warbands for his Christmas, and where, second episode, a Saxon party retaliates and attacks the longships left with a small guard.
There is also a Learn to Play Ravenfeast video where the rules are detailed and put into practice before our eyes. The quality of the videos is great... and the Little Wars guys have an awesome gaming room (jealous).
The rulers are put into heavy use during moving and shooting, I'd suggest using sticks, 6" and 8" (slaves) for measuring movement and range (javelin 8", bow 3 times 6").
The game is meant primarily for 28mm, 1 miniature 1 man, skirmishes and features stats for Norse and Saxon warbands. The units/soldiers go from jarl/earl to thrall/slave, with some bersekers if needed.
One has to roll low, a missile or a mêlée attack d6 has to result in a number lower or equal to its attack score. The target then has to roll a d6 lower or equal to its armor score. In mêlée, if an attacker rolls a 1 and the target rolls a 6, the attacker is granted a free attack against the same target. If that second attack succeeds, the target is marked with a Raven token, it's a "Death Worthy of a Song". At the end of the turn, all figures within 6" of the token have to roll for morale.
A figure takes one wound unless it has the Tough attribute, usually it's a Jarl or hero figure.
It looks simple and fun. It's meant as an introduction to miniature historical wargaming and it seems it delivers.
There are three scenarii at the end of the booklet and also instructions on how to build a model longhouse. The separate cheatsheet PDF is condensing the 6 pages of rules into two.