Challenge rules

Cap it. Five rungs is the default here, and every published club ruleset we surveyed caps it somewhere. Uncapped ladders produce a 3.0 challenging a 4.5 in week one, which is a bad hour for both of them and the fastest way to lose a new member. Tighter caps (three rungs) make the ladder climb slowly and reward patience. Wider caps (eight or more) make it volatile. Rule 3.

Not on a well-run one. Upward only. Let challenges run downward and the strongest player in the band farms the bottom of the standings for safe wins, which is exactly the behavior a ladder exists to prevent. Play a friendly against whoever you like. It does not move the standings.

Nothing, if the ladder is built correctly. The clock expires and the challenger takes the result as a walkover, without an organizer adjudicating and without anybody emailing an administrator for permission. If you are running this in a spreadsheet, write the rule down before the season starts and apply it the first time it happens. The first unenforced deadline teaches everyone that deadlines are optional.

A rematch cooldown. Fourteen days by default. Without one, two friends at rungs 6 and 7 can play each other every three days, swap positions on each result, and climb past the rest of the band on volume alone. The cooldown does not stop them playing, it stops those results counting twice in a fortnight.