Battlefield removal (or BFR) refers to the act of one character forcing their opponent out of the established fighting area, resulting in a default win.
If the battle arena has established physical boundaries that the fighters aren't allowed to cross, then a BFR can be achieved by forcing the other person to cross those boundaries. Some examples of this would be:
- The Hulk punching his opponent out of bounds
- Shikamaru using shadow possession to make his opponent cross the boundary
- The Flash bringing Gorilla Grodd into the Speed Force with just his mind.
If the battlefield doesn't have established physical boundaries, achieving a BFR is tougher and less likely, but not impossible. Generally, it's done by trapping the other person in another time or dimension. Some examples of this are:
- Kakashi using kamui
- Obito Uchiha using space-time migration
- The Doctor trapping someone in a time loop