In Battlestar Galactica season two episode four Resistance, Starbuck and Samuel Anders play a pickup game of Pyramid. The two seem to be following a set of rules, but nothing is clearly outlined in the episode. Are the rules of Pyramid ever explained? If not explained in universe have they been outlined elsewhere? Does anyone actually play this "sport?"
Yes, there are rules to the game, though no single episode explains them all.
The Battlestar Galactica Wiki says:
Pyramid is a close quarters ball game played on a pyramid-shaped court, hence the name of the game. The objective is apparently to score points by getting the ball into a goal at the top of the pyramid. Pyramid can be played one-on-one or in teams.
Players can take no more than "three paces" without passing, shooting, or rebounding the ball off of one of the walls. The outlined areas in the corners and the center of the arena are "neutral zones". When a player places the ball in these zones, other players must back off and may not make contact.
Full contact is allowed (when the ball is not in a neutral zone), and once a player has been tackled, they must pass the ball. How this is handled in one-on-one games is left unspecified. The game is won by the team with the most points at the end. However, under what circumstances the games ends is also left unspecified.
There are versions of pyramid for one, three or five players from each team on the court at once. The play area is consistently referred to as an "arena" and the corner with the goal as the "head".
Apparently each team starts out in one of the corners besides the head and then vie for control of the ball. The initial ball placement is not defined, but a face-off is mentioned tangentially later in the article with no details.
REF: A compiled source reference comes from Battlestar Galactica: The Official Magazine, issue 1, pp. 28-29
Pyramid has also enjoyed a present day, playable variant which shows the game in action with all of its peculiarity. A sporting group lead by the Colonial Triad League, posts their own rules and playing area schematic. A full list of their Pyramid Rules can be found here on their rules website page.
From the video, the game certainly seems playable with a lead-in bouncing pass (for variability in the kickoff) and the required bounce before any attempt at a goal keeps the game variable, unpredictable and best played by those with decent hand-eye coordination.