Aging

Aging is applied at character creation and every time a character ages 1 year (naturally or unnaturally).

Some important notes:

1)
DMG 13.
2)
For example, if the Young Adult loss of STR would put a character below their STR minimum, but the Mature gain of STR would put them back at their minimum, the new character should be at their minimum (i.e. both the -1 and +1 should be applied). But if the character hits Mature during play, the +1 STR should be applied even though the character didn't lose the -1 during character creation. Put another way, there is no need to track being “in the hole” for aging, and there should be no occasion for a player to note on their character sheet that they “owe” a point of STR.