contract (law)

A contract is a promise the law will back up with its muscle. Buy a coffee, rent an apartment, take a job — each is a deal where, if one side breaks their word, the other can march into court and demand the promise be kept or the loss paid for. There is one more quiet requirement: both sides have to actually mean to be legally bound. That intention is why a casual "sure, I'll help you move on Saturday" between friends usually isn't a contract at all — nobody expected a judge to get involved.

The classic recipe has three ingredients. One side makes an offer ("I'll sell you my bike for $100"); the other accepts it ("deal"); and something of value passes both ways — that's consideration. Each side has to give something to get something: my bike for your money. A bare promise to hand over a gift, with nothing flowing back, usually isn't a contract the courts will enforce.

A common myth is that a contract has to be a thick document bristling with signatures. Most contracts are spoken or sealed with nothing more than a handshake or a tap of a card, and they bind just the same — though some kinds must be in writing to be enforceable, such as the sale of land or a promise to cover someone else's debt (a rule known as the Statute of Frauds). For the everyday deal, though, the written page matters less for making the agreement than for proving, later, exactly what everyone agreed to.