Requires 2 GMs and 1d4. Later, players may be involved.
A) Each GM creates a game world.
B) Each GM describes their world to the other.
C) The younger GM chooses a location in the older GM's world for the conjunction of the worlds to occur.
D) The older GM chooses the location for the conjunction in the younger GM's world.
E) The GMs exchange ideas for what happens next. If they disagree, roll the d4:
1: Younger GM's idea happens and younger GM gets to describe it.
2: Younger GM's idea happens and older GM describes it.
3: Older GM's idea happens and younger GM describes it.
4: Older GM's idea happens and older GM describes it.
F) Repeat step (E) as long as it is fun. Consider the effects of the different gods, philosophy, popular culture, technology, magic, biology, resources, and anything else that seems fun.
G) If the GMs feel like it, they can stop Worlds Collide and start a campaign or two with actual players in media res.
Hope you are doing well!