Room of Spirit and Time
 Plot involvement
Located in another dimension, the ROSAT is said to present an individual with their toughest challenge in their lives. Inside the room, you spent one year whilst on the outside, only a day passes, making it the ideal place to gain huge power-ups in a short timespan. The circumstances in the room vary from time to time. For example, one instance it can be boiling hot, whilst it could be freezing minutes later. Furthermore, the ROSAT is said to have a gravity level far greater than Earth's. All these factors combined make it a huge test for everybody who enters, both physically, and mentally. Every character who trained in this room came out much stronger than ever before, proving the room's reputation to be justified.
In order to use the ROSAT for training, one must consider the following requirements at all time:
- A person can use the room only twice in their entire lifespan.
- Only two people can enter the room at a time.
- You can only train 24 hours on end. If you don't exit the room before the 24 hours are over, the entrance will disappear, and you will be sealed away in another dimension forever. If your ki is high enough though, you can yell loud enough to breach a hole in the dimensional barrier, allowing an escape. The villain Majin Buu, and the fused character Gotenks displayed this ability, though the latter had to use Super Saiyan 3 to be able to do so.
- Destroying the entrance will also result in lifelong imprisonment in the room.
 Characters that used the ROSAT
Note: entries are listed in chronological order. Goku's first entry is not shown in the manga, but it is referenced, so it counts as canon.
- Goku (in Dragonball Anime Filler)
- Vegeta (in order to surpass Super Saiyan)
- Future Trunks (in order to surpass Super Saiyan)
- Goku (in order to surpass Super Saiyan) (2nd entry)
- Gohan (in order to surpass Super Saiyan])
- Piccolo (in order to power up for the Cell Games)
- Vegeta (in order to power up for the Cell Games) (2nd entry)
- Future Trunks (in order to power up for the Cell Games) (2nd entry)
- Goten (in order to power up for the upcoming clash with Majin Buu)
- Trunks (in order to power up for the upcoming clash with Majin Buu)
- Gotenks (fusion of Goten and Trunks)
- Piccolo (to guide Majin Buu to the room)
- Majin Buu (to fight Gotenks)