Line Game (Spaderspiel) requires a sandy beach, two regular beach spades (long), and several willing participants (preferably small children, the easily-entertained, or persons of a lower IQ than most).
The game is a test of endurance and Intelligent Symbolism™. One person (usually the game's initiator) is the Spader; they take the spades and control the entire game. Everybody else is, in essence, the Spader's bitch.
The Spader walks or runs up and down the beach at free will, dragging a spade either side of his feet. Everybody else follows the Spader, for he is their leader. When following the Spader, feet must only fall on the lines provided: the left-hand line for left feet, and the right-hand line for right feet.
Failure to keep feet on the lines will result in disqualification or verbal punishment at the Spader's discretion.
The Spader may switch the spades around at any point, crossing the lines over in the sand.

This forces the Followers to walk cross-legged.
The Spader may choose to retract one or both of the spades from the sand for a brief period of time, creating a gap in one or both of the lines. The Followers must hop or jump their way over these markings, bearing in mind that one misplaced foot may cost them the game.

The Spader may choose to retract and replace both of the spades in and out of the sand in a fast, repeated motion across a particular stretch, creating a pair of dotted lines. This forces the Followers into a ridiculous-looking foot shuffle. The more ridiculous the shuffle, the better the player, and the lesser the chances of disqualification.

The Spader may choose to mark the edge of the line set with symbols: little sets of lines that have different instructions associated with them. The instruction is decided entirely by the Spader on the first appearance of a new symbol. He will shout out the instruction, and the Followers must remember it and associate it with that symbol thereafter.

ONE MARKING EITHER SIDE invariably means "turn around and walk backwards".
TWO MARKINGS EITHER SIDE will usually mean "break out into a song of the Spader's choosing", but has also been known to mean "crawl" or even "switch feet". (Fierce debate has been known to exist between professional Spaders who have always been divided on the 'correct' usage of the 2-marking ever since the game's inception.)
THREE, FOUR, FIVE OR SIX MARKINGS EITHER SIDE can mean anything the Spader wants it to mean. He is God; he is to be obeyed at all costs. Different Spaders apply different instructions to symbols, and regular players will soon learn the way the Spader's mind operates, almost to the point of pre-empting their movements to the nearest degree.
The deadliest Spaders know how to catch their victims out. They are always looking for fresh new ways of trapping their prey and disqualifying everyone in sight. Scenes of carnage such as these are not uncommon:

The only way to survive a Line Game is through a craftily-balanced mix of skill, perseverance, eptitude, lateral and longitudinal cogitation, juxtaposition, je ne sais quoi and double entendre.
A Follower can be disqualified at any time for any of the following reasons:
- Not keeping their feet on the marked lines.
- Becoming separated from the rest of the pack.
- Failing to correctly obey the instructions associated with the symbols provided.
- Singing out of tune or missing a key change.
- Calling the Spader nasty names like "big fat poohead".
- Kicking other Followers in the shins to lessen their chances of qualification.
- Gross consumption of Mr. Whippy in front of other Followers.
A Follower is said to qualify if:
- They aren't disqualified.
- The Spader can no longer be arsed to play anymore and he wants to have a sit down for a bit. This is fair enough, really, considering how tiring it must be for him.
Coronation occurs when the Spader is thoroughly satisfied that one of his Followers is worthy enough to take over the role of Spader. The act of coronation is conducted through a ceremonious ritual involving the Sacramental Passing of the Spades. From that point onward, the retired Spader must thereafter be addressed as the Spader Mother. The Spader Mother must be consulted on all future decisions regarding the passing-on of Spadership, and must also be supplied with plentiful quantities of Mr. Whippy upon request.
The game is to be taken highly seriously at all times. Failure to take the game seriously will result in the game being Sillied (named after the great, noble Lord James Sills of Walden), after which point the game is not to be taken seriously. If the game is taken seriously after the game has been Sillied, you will be laughed at.