"Finders keepers" is an expression that suggests that if someone finds something accidental, they may keep it as their own. However, there are several synonyms for the phrase. One of the most common is "possession is nine-tenths of the law" which means that whoever possesses something has a stronger claim over it. Another phrase often used is "losers weepers" where the one who lost the object is encouraged to accept it as a loss. "First come, first served" is another phrase that expresses the notion that whoever finds something first gets to keep it. In summary, although finders keepers is a common phrase, there are many alternatives that can be used to express the same sentiment.