For this game, we need two layers of ruleset: One that applies to all branches that describes how the gameplay between rounds works and one that is tracked per-branch. Let's call the upper ruleset the "Constitution" and the lower rulesets the "Branch Rulesets"

Constitution

On Branches

A "branch" is a game within this nomic which has its own set of governing rules. Players of this round can subscribe to any branch that they aren't already subscribed to so long as no constitutional rules disallow it. Subscribers to a branch can unsubscribe from that branch so long as no constitutional rules disallow it.

Branches have a weight, which is a real number less than 1. When one player wins in a branch, they gain a proportion of victory equal to that branch's weight. When more than one players win in a branch, those players each proportions of victory equal to that branch's weight divided by the number of players who won in that branch.

Whenever there is a disagreement over the interpretation of an aspect of a branch's ruleset, if three or more subscribers to that branch agree on an alternate interpretation, then that branch is split. Additionally, whenever a branch proposal is resolved and is not unanimous, and at least three peoples' votes are contrary to the outcome, then that branch is split.

When a branch (the predecessor) is split, it is destroyed and two new branches are created, each with half the weight of the predecessor. Every subscriber to the predecessor becomes a subscriber to the new branch that fits their opinion on the rule change or interpretation that led to the branch's split.

Branches cannot:

Change the weight of any branch.
Disallow players from subscribing to or unsubscribing from any branch.
Award proportions of victory, except in the case that one or more players have achieved victory in that round.