Direct Day Deadlines
Direct Day Deadlines (DDDs) are day phase deadlines that are directly proportional to the number of players alive in real life days. Aka, as more players die, day phases become shorter. This means that, for every 1 player alive, the day phase will last 24 hours. The purpose of these deadlines is to eliminate the problem where games tend to stagnate in the late game as there is a low amount of players left who still have ages to decide on a lynch.
DDDs do not affect the length of night phases.
Many moderators would use DDD+n rules where n is a number decided on by the mod. This means that, for every 1 player alive, the day phase will last 24 hours + 24*n. As an example, in a 13 player game, the mod may want the initial day length to be 14 days (2 weeks) which is the current site standard. As a result, they would use DDD+1 so that for every 1 player alive the day phase will last 24 hours + an additional 24 hours.
Some moderators may also impose maximum or minimum day phase lengths. For example, in large games, DDD rules may become a bit excessive as 3 week+ long day phases are not needed. Instead, the moderator may specify that there is a maximum of a 14 day limit on the DDDs. This means that usual DDD rules will apply only after the number of players left drops below a specified amount.