Otherworld Rift is a location in the World that is only open on certain system dates on the computer running the game[1]. On these dates listed below (or by setting the computer time to these dates), certain rewards can be obtained from adventuring into the location. This restriction can be removed by using a Mod.
Adventuring to the location outside of these dates will result in nothing happening. Despite the description, Luck is not required to receive any of the rewards.
Unlocking Otherworld Rift location[]
A Secret "Disturbance of the Otherworld" appears on Day 25 at Seascape, completing it unlocks the Otherworld Rift[2].
Otherworld Rift full of festive spirit[]
Once per game, during Chinese New Year (from 14 days before to 14 days after the holiday date)[1], or at any time during year 2031 or later[1]:
Gain 15,000 Inspiration
Gain Manual Illustrated Book of Coming Spring
Otherworld Rift full of majestic spirit[]
Once per game, between October 1 and October 7[1] (China's National Day):
Gain 50,000 Inspiration
Gain Manual A Comprehensive History of Serica
Otherworld Comer[]
On Day 120, this Secret appears at Otherworld Rift. Adventuring there unlocks the Heaven Echo Altar Building[3].
Otherworld Tales[]
On Day 375, this Secret appears at Otherworld Rift. It requires 500 Attainment to complete and unlocks a challenge area "Rift Between Worlds: Village of nowhere"[3].