"Play false" has a negative connotation and implies deceit or dishonesty. Thankfully, there are many alternative phrases that can be used to convey the same meaning without resorting to this harsh language. Some synonyms include "act deceitfully," "betray," "cheat," "deceive," "trick," "mislead," "double-cross," "hoodwink," "dupe," and "swindle." These words accurately describe behavior that violates trust, breaks promises, or seeks to gain an unfair advantage over others. When choosing the appropriate synonym, consider the context and severity of the situation to ensure your language is appropriate and effective.