Answer:
An imaginary sport could be called "mix-ball". In this game, we have 4 players who are from different parts of the world who play different games using different balls. For example, the first player could be from mexico and plays soccer, the second is from the US and plays football and the third is from Puerto Rico and plays baseball. The last is from Australia and plays tennis. This game is centered around the rules of baseball. This game works by having 4 bases like in baseball but each player has to use a different ball each time they throw. They have to throw it as far away as possible also like in baseball. Every time to person throws it far enough away, they have to run to the first base and have to go four times in a row each time using a different ball (aka mixball). Once you have used all balls and finished reaching all the bases, you win a mixed run! The rules of this game are to use all balls and hit the "home run" (which is actually called the "4-ball mix run" in this game) every time for every ball run. They only way to be out or lose is by getting tagged by the people who catch the ball (these will be the other three players).
Step-by-step explanation:
Hope this helps and use your imagination to change or add some things if you'd like. Also the theme of this game is diversity aka the differences between people and sports' cultures.