Ask “which version?” first
The name “ladder game” does not settle every detail. Page title, settlement unit, result categories, payouts, and timestamps can vary by version.
Break the rule into fields
Record participation, result fields, odd/even or three-gate definitions, payouts, settlement conditions, and void handling separately.
Store records with the rule
Bind historical rows to the rule version. If the rules change, split the record set instead of treating a product change as a probability change.