In your pretend shop, a scrap did not automatically buy a pencil. The shopkeeper needed a reason to accept it. When you agreed on a token rule, the same piece of paper could do a new job inside the game.

Money is accepted payment. People can use it to buy things without offering a direct swap that the seller wants. It also gives a shared way to name prices. A price tells how much money is asked for something.

US dollars belong to an official money system. Your game token belongs to your game. A private agreement does not turn a scrap into an official dollar or make every shop accept it.

A dollar is a unit of money, not a fixed bundle of things. The amount printed on a bill stays the same when a shop changes a price. What that amount can buy may change. Your game lets you test acceptance; it cannot explain every reason a national money system works.

Your token was ordinary paper. A US bill uses paper made from cotton and linen. Its material differs from a usual writing sheet, but material alone does not give a blank piece the value of a dollar.

US currency is not now redeemable for gold. Redeem means exchange under a promised rule. Holding a dollar does not give you a right to swap it for gold at the government.

Another phrase you might hear is legal tender. In the United States, this concerns payment of debts and other public charges. It does not mean federal law makes every private business accept cash for every purchase. Local rules can differ.

That brings us back to the opening puzzle. The bill is part of an official system of payment. Your paper token works under a small rule you agreed to for play. Cotton and linen explain the bill’s material. Gold redemption and legal tender describe different rules. None makes a blank scrap an official dollar.