The phrase “pass the buck” originates from poker games in 19th-century America.

In poker, a “buck” referred to a marker (often a knife with a buckhorn handle or later a silver dollar) that indicated whose turn it was to deal. When a player was finished dealing, they would “pass the buck” to the next player.

To avoid dealing, a player might literally pass the responsibility — thus, the phrase came to mean passing responsibility or shifting blame.

By the late 19th and early 20th centuries, “pass the buck” had become common slang for evading responsibility in general.

President Harry S. Truman popularized the opposite expression — “The buck stops here” — to indicate personal accountability. He even had it on a sign on his desk in the White House.

So, in short:
“Pass the buck” = dodge responsibility
“The buck stops here” = take responsibility

Thanks for reading and learning something new.