Board Thread:Questions and Answers/@comment-5956954-20151218115701/@comment-27452150-20151218122624

The GAME started when Frisk fell, not the TIMELINE. Here's the timeline:

????: Monsters VS Humans, Humans win. =TIMELINE START=

????: First SOUL falls down, poisons themself.

????: Second SOUL falls down, gets killed

etc., until you get to Frisk. =GAME START, PACIFIST=

201X: Frisk falls down, befriends everyone, ASRIEL breaks the barrier with the SOULs.

Or... =GAME START, KILLER=

201X: Frisk falls down, goes on a killing spree, possesed by Chara.

Hope that works.