1. When a debt is unliquidated (in dispute) as to the amount owed, a debtor who sends a check and marks the check "paid in full" will not be liable for any balance owed under the doctrine Accord and Satisfaction once the check is deposited/cashed..

2. There is no need for consideration in an "option" contract.

3. If you sell a used car the buyer receives the implied warranty of merchantability even if nothing about warranty is mentioned.

4. The UCC ("Uniform Commercial Code") sales articles apply to mixed goods/service contracts if the predominant part of the contract is the sale of goods.

5. The "Mailbox Rule" states that an offer is accepted when the acceptance is mailed (if the means are authorized) NOT when received.

6. A buyer can seek "Specific Performance" of a contract if the item is unique.

7. If you are under 21 years of age, you do not have the capacity to enter into a contract so your guardian would have to enter into the contract on your behalf.

8. If a lease has been assigned ("sub-let"), the landlord has the right to pursue both the lessee and the sub-lessee for payment of the rent even if the landlord was not a party to the sub-lease.

9. If a tenant breaches his one- (1) year lease with his landlord after six months the landlord must make an effort to relet the premises under the doctrine of Liquidated Damages.

10. Failure of consideration is a real/universal defense against a holder in due course of a negotiable instrument.

11. Under the UCC, a seller and a buyer of goods may agree to leave the price terms of goods open in their contract and still have an enforceable contract.

12. Once an offer has been accepted, that acceptance cannot be revoked.

13. Entrusting goods to a "merchant" under the UCC empowers him to transfer ownership rights to a buyer in the ordinary course of business.

14. The Commerce Clause of the United States constitution authorizes the Federal Government to regulate intrastate commerce.

15. An "IOU" is enforceable but not negotiable.

16. Banks are allowed by the UCC to pay postdated checks even before the date written on the check.

17. Silence can be acceptance of an offer.

18. A contract with an unemancipated minor (under 18 years old) is VOIDABLE by either party to the contract.

19. A negotiable promissory note is still negotiable even though it is secured by a real estate motrtgage.

20. In an auction "without reserve", the highest bid is the acceptance of the offer