The Modern Rules still resemble the first codified rules of 1863.

THE CAMBRIDGE UNIVERSITY RULES NOVEMBER 1863

Rule 1
The length of the ground shall be not more than 150 yards. The ground shall be marked out by posts, and two posts shall be placed on each side line, at a distance of 25 yards from each goal line.

Rule 2
The goals shall consist of two upright poles at a distance of 15 feet from each other.

Rule 3
The choice of goals and kick off shall be determined by tossing, and the ball shall be kicked off from the middle of the ground.

Rule 4
In a match when half the time agreed upon has elapsed, the sides shall change goals, when the ball is next out of play. After a change or a goal obtained, the kick off shall be from the middle of the ground in the same direction as before. The time during which the match shall last, and the numbers on each side are to be settled by the heads of the sides.

Rule 5
When a player has kicked the ball, any one of the same side who is nearer to the opponent's goal line is out of play, and may not touch the ball himself, nor in anyway whatsoever prevent any other payer from doing so.

Rule 6
When the ball goes out of the ground by crossing the sidelines, it is out of play, and shall be kicked straight into the ground again from the point it is first stopped.

Rule 7
When a player has kicked the ball beyond the opponent's goal line; whoever first touches the ball (touchdown) when it is on the ground with his hands may have a free kick, bringing the ball 25 yards straight out from the goal line.

Rule 8
No player may touch the ball behind his opponent's goal line, who is behind it when the ball is kicked there.

Rule 9
If the ball is touched down behind the goal line and beyond the line of the side posts, the free kick shall be from the 25 yards post.

Rule 10
When a player has a free kick, no-one of his own side may be between him and his opponent's goal line, and no-one of the opposite side may stand within 10 yards of him.

Rule 11
A free kick may be taken in any manner the player chooses.

Rule 12
A goal is obtained when the ball goes out of the ground by passing between the posts had they been of sufficient height.

Rule 13
The ball when in play may be stopped by any part of the body, but may not be held or hit by the hands, arms, or shoulders.

Rule 14
All charging is fair; but holding, pushing with the hands, tripping up and shinning are forbidden.

Differences with the modern game

In addition to the simplicity of the Cambridge Rules, there are several other important differences with the game of football we know today.

Although there were usually 11 players, there was no rule to stipulate this, or even that the two sides should have equal numbers. In fact, it was not uncommon for games to be played with unequal numbers.

The goals consisted of two uprights with no crossbar. A goal could be scored if the ball passed between them at whatever height in the same way as a conversion kick in rugby.

The off side rule was the same as in rugby ie if a player was in front of the ball, he was off side, so no forward passes to team mates were possible. This meant that members of the same side formed up behind and on either side the player with the ball ­ a tactic called 'backing up'.

Players could not catch the ball, but could stop it with their hands. When the ball was kicked over the goal line whichever team touched it down first got a free kick 25 yards in from where it was touched down. If the attacking team achieved such a 'touch down', it represented an excellent opportunity to score a goal.

There were no throw-ins: the ball was kicked back in from where it was first stopped.

All shoulder barging was fair and it was therefore possible to barge a player who was in possession of the ball, rather than going for the ball itself. Likewise, on 50/50 balls, players shoulder barged in a much more aggressive way than would occur in today's game.