This WinCon condition is most of the times equivalent to Last Standing for factions with a Group Kill e.g. for Baddies. It is considered fulfilled if the number of own faction members left alive is greater than the rest of the alive players before a night or a day cycle. Being in majority typically allows for a successful lynch of the other faction members, coupled with their Group Kill, hence the game is considered finished (actually fast-forwarded).
However, the endgame is actually clear only if it cannot be changed (assuming optimal play from the informed minority) by any set of actions or votes from the other factions or tie lynch rules. The presence of vote manipulators and saving roles in the game makes being in majority harder to anticipate by any faction and trickier to judge by the host.
Hosts should not rule this WinCon as fulfilled:
- before a day, if vote manipulation or tie lynch rules can still get a baddie lynched
- before a night, if there is a doctor or resurrect role still alive, or any other ability which can interfere with the NK or affect the balance number-wise.