Rolz.org allows anyone with the room name to join in so you can also have the Overseers join. While we'd (people in general) hope everyone would just be honest: It's best to have a ref/overseer present as well. Though, as to the main question: yes, you will be able to see all other rolls done in the room.
You can also tag your rolls, in 2 v 2 (or more) it's common to put
Miah: /1d100 #Attack @ Nahv'ir
Nahv'ir: /1d100 #Defense @ Miah
Helps so that people know where the attack is going and the defense for if the in-game text if flying by too much with other players. Helps the ref keep tabs on HP counts or hit counts as well.
You can also tag your rolls, in 2 v 2 (or more) it's common to put
Miah: /1d100 #Attack @ Nahv'ir
Nahv'ir: /1d100 #Defense @ Miah
Helps so that people know where the attack is going and the defense for if the in-game text if flying by too much with other players. Helps the ref keep tabs on HP counts or hit counts as well.