THE PLAYING FIELD: as big as you want, rough or smooth, full of trees or a football pitch, whatever you have available. The centre of the field ideally is visible from either end.
THE GOALPOSTS: two round viking shield with shield bosses (though I daresay you could play with a different pair of shields if you felt like it.
THE BALL: it's not a ball it's a spear referred to as THE SPEAR
THE TEAMS: two teams with as many players per side as you can persuade to join in.
THE OBJECT OF THE GAME: to hit the opponents shield boss with the spear. Each time this is done a point is awarded and the teams take up the starting position again.
STARTING POSITION: the teams line up each team behind their own teams shield (the one being used as the goal). They may not move past their shield until the start of the game is signalled.
TO START THE GAME: someone who is in neither team stands in the middle of the pitch between the two teams and throws the spear in the air. Play starts when the spear lands. If the field is too big or overgrown for the teams to see the spear land, the starter blows a horn to signal the start.
THE RULES:
You may not use THE SPEAR to kill anyone, nor may you use it to block a blow. (Variations on this rule may be agreed upon.)
You may not throw THE SPEAR.
If you are a fighter you may kill any other fighter in the game, (though it's usual to only kill fighters on the other side :-) normal combat rules apply for fighters killing fighters.
If you are a fighter you may kill any non-fighter by touching (not hitting) them with your weapon.
If you are killed you must remain on the ground until a goal is scored, (you may crawl away if you risk being trampled, but you may not deliberately crawl into the way of someone still alive.
Hiding THE SPEAR, confusing the other team by introducing other spears, etc. is permitted.
Non-fighters are not allowed to tackle, wrestle, or otherwise grab one another or fighters. They are allowed to lie or stand in the way of anyone, and they are allowed to grab THE SPEAR.
The shields forming the goal posts may not be moved.
CHEATING: there are two alternative approaches: one is to encourage as much cheating as possible. The other is to have referees and to penalise cheating by awarding points to the other side.
TACTICS:
non fighters tend to be faster than fighters, so they are often used as spear carriers. However they are defenceless, and need heavy escorts when they get near the opponents shield.
Introducing dummy spears not only confuses the opposes team, but it can be a good way to kill them, as they think they cannot be struck with a spear assuming it is THE SPEAR
If you have a good supply of non fighters suicide squads can be used to slow down spear carriers.
Suicide squads may also die on top of their team's shield. This makes it very awkward for the other team to hit the shield boss as they have to be picked up and moved. As they are dead they may not resist being moved, but it is an excellent delaying tactic.