Because of different possibilities and different choices, countless parallel universes have been split.
If the territorial war is defeated, another race may rule the planet;
The emperor made a decision and may have promulgated new laws accordingly;
A step slower when crossing the road may change life or death;
Scientists conducted different experiments that may have accelerated the development of technology;
…
Zerg, ancient times, campus, interstellar... Independent unit stories in different worlds
Purpose: cherish the present moment