Contracts typically include key elements:

1. Offer and Acceptance: One party must make an offer, and the other must accept it.

2. Intention to Create Legal Relations: Both parties must intend for the contract to be legally binding.

3. Consideration: Something of value must be exchanged between the parties.

4. Legal Capacity: Both parties must have the legal capacity to enter into the contract.

5. Legality of Purpose: The purpose of the contract must be legal.

6. Certainty and Possibility of Performance: Terms of the contract must be clear, and performance must be possible.

7. Mutual Consent: Both parties must agree to the terms without duress or misrepresentation.

Remember, the specific requirements can vary based on jurisdiction and the type of contract.