- Hamilton: As per history, Hamilton endorses his longtime political foe Thomas Jefferson for President against their common rival Aaron Burr. The show makes a point of hammering home Hamilton's reasons for this — as much as he dislikes Jefferson's ideals, at least Jefferson has ideals.Hamilton: "I have never agreed with Jefferson once
We have fought on like seventy-five different fronts
but when all is said and all is done
Jefferson has beliefs — Burr has none."
- In Reds and Blues, the two families of feuding Liverpool and Everton supporters (and the audience, who are likely to be similarly split) briefly join together when a Manchester United fan shows up.
- In The Taming of the Shrew, several men are rivals for the hand of the fair Bianca, but her father won't let any of them marry her unless her shrewish older sister, Katarina, is married off first. Realizing that there's no point in fighting each other if they don't have a chance, the suitors decide to work together to get Katarina a husband.
- Played with in Coriolanus. After the title character is banished from his native Rome, he teams up with his former nemesis Aufidius (and just to be clear, these guys hate each other so much that they've each sworn repeatedly (and graphically) to kill the other) in order to help Aufidius conquer Rome. It doesn't work out for either of them.
Enemy Mine / Theater