Flip chests for SSR weapons/summons are notorious for having abysmal drop percentages (the most commonly cited number is 2%). However, depending on the boss being killed, they also usually guarantee a rare item of some sort.
Tier 1 Raids Edit
The commonly farmed Omega raids have a possibility to drop 2 flip chests normally, with the vice MVP gold chest also given a chance to flip. The two normal flip chests are separate (in other words, there is an infinitesimal chance that you can get both of them at once), and the loot from one of the two chests is known to always be an Omega summon, while the other chest has one of the four Omega weapons associated with that boss. The vice MVP flip chest can be either a weapon or a summon.
Tier 2 Raids Edit
There isn't as much data on the tier 2 raids yet, but what is known is that they do not drop Omega summons, but have added the tier 2 raid weapons to the pool. The assumption, then, is that there is only 1 possible flip chest that can contain any of the 6 weapons. There is another flip chest that drops Omega Animas.
Tier 3 Raids Edit
Same as tier 2, there isn't as much data on the tier 3 raids yet, and they drop Omega weapons in addition to tier 3 raid weapons.
Rank 80 Raids Edit
Proto Bahamut and Grand Order switch things up a bit since they can drop rare crafting materials, which also come from a flip chest. Supreme Merits and Blue Sky Crystals, unlike previous flip chests, replace normal drops (usually Champion Merits) and eschew the 2% drop rate, while the Horn of Bahamut replaces the guaranteed Rusted Weapon drop but still has a very low drop rate.
|Proto Bahamut||Grand Order|
| Horn of Bahamut|
Bahamut Weapons (0★)
| Twin Elements Omega Anima|
Macula Marius Omega Anima
Medusa Omega Anima
Nezha Omega Anima
Apollo Omega Anima
Dark Angel Olivia Omega Anima
Blue Sky Crystal
Impossible Raids Edit
For the tier 1 raids, in addition to the same summons/weapons as the Extreme versions, they also have a 100% chance to drop matching-element Centrums, which always flip.
For the tier 2 raids, in addition to the same weapons as the Extreme versions, they also have a 100% chance to drop matching-element Urns, which always flip.
Maniac and Nightmare bosses have a low chance to drop Urns corresponding to the boss's element in flip chests. In addition, Very Hard and above bosses can drop event weapons and/or summons from flip chests, with higher difficulties having higher chances. The rate of event flip chests is much much higher than 2%.