Write a one-sentence explanation for the following phrase: "Zero-sum game".
A Zero-sum game is a situation in which one participant's gains result only from another's equivalent losses.
Complete the following task based on the instruction and optional input provided.### Instruction:
Write a one-sentence explanation for the following phrase: "Zero-sum game".

### Output:
A Zero-sum game is a situation in which one participant's gains result only from another's equivalent losses.