Extra busy day, so I’ll add to my answer for Day 2 Change. For my alternate SFRPG that was similar to the TV show Mortal Kombat: Conquest, characters could receive Blessings and Curses.
One favour a PC could have was the power to choose to reroll any failed test once, however, the God could then require a later important successful test to be rerolled. Until the God required the reroll, this blessing could not be used. It added some interesting tension for the PC, also it presented the puzzle: is the God basing it upon what is important to them, or the character? The uncertainty helped emphasis the Blessing and Curse nature of this Favour.
Other Peoples’ Answers
Anthony Boyd @Runeslinger
Heather Fey @slapjellyfish
Charles Etheridge-Nunn @charlie_en
Bob Freeman @OccultDetective
Craig Oxbrow @CraigOxbrow
John M. Kahane @jkahane1
Sue Savage @SavageSpiel
Geek-Life Balance @cybogoblin
This is a non-exhaustive list; I still have many posts to read today, so I might be adding more links. I’d recommend searching the hashtag and judge those great answers for yourself: #RPGaDay2020, some people use #RPGaDay.