Besides the Conflict between the protagonist and antagonist/situation, the most common form of conflict is between allies. It would not only take away the suspense, but also the depth, to have everyone on one side working as one, with no problems. Thus the heroes and the villains have conflict with each other, and the side that usually wins is the first to Overcome Their Differences.
The difference can be between allies, between friends, between leaders and subordinates, between lovers or between those who are falling in love.
But it's still essential in many stories. It looks all the more triumphant for the winning side to get past such a major obstacle. This is especially true when the differences are the antagonist of the story instead of a person, such as in many romantic comedies, and every Buddy Cop Show and movie.
- The super-villain duo Hammer And Anvil in The Incrdible Hulk were a white racist who was chained to a black man who hated everyone but they hated prison more and worked together to escape, the results of which led them to an alien giving them super-human powers by transforming their prison chain into a source of powers for them. While they hated each other they overcame those differences because it benefited them overall.
- Done beautifully with Kristina and Ulrika in The Emigrants.
- Anaak and Hatz from Tower of God. At least it appears so at first, but one is still a loose cannon and the other a condescending stick in the mud.
- A prevalent theme in Dubious Company. Just about any character pairing will need to do this to save the day or help each other Take a Level in Badass. Tiren and Walter, Elly and Walter, Sal and Tiren, Leeroy and Sal, Marty and Gary, Sue and Mary, Marty and Sue, Mary and Gary, & Walter and Izor are the most reoccuring examples.
- The love interest variant is mentioned in item 98 in the Evil Overlord List.
- "If an attractive young couple enters my realm, I will carefully monitor their activities. If I find they are happy and affectionate, I will ignore them. However, if circumstances have forced them together against their will and they spend all their time bickering and criticizing each other except during the intermittent occasions when they are saving each other's lives at which point there are hints of sexual tension, I will immediately order their execution."
- The basis beyond several Teen Titans episodes such as "Divide and Conquer", "Forces of Nature", and "Switched".