Is it possible to have an agreement to agree? From the bus in the morning, to that mid-afternoon pick-me-up coffee, we constantly enter into informal "contracts" or "agreements" with others. These transactions benefit from certainty. Pay £1.80 and you will receive a bus ticket. Simple. But contracts can be much more complex than this.
We still see many formal contracts with startling degrees of informality and uncertainty in the drafting.
The question of how much certainty a contract must have to be enforceable was tackled