Read about the differences between unilateral and bilateral contracts. Then decide if the contracts listed below are unilateral or bilateral.

English contract doctrine distinguishes between bilateral and unilateral contracts. A bilateral contract gives rise to obligations on both sides. Thus in a contract of sale, the seller has an obligation to transfer title in the thing sold to the buyer, whilst the buyer has an obligation to pay the price. A unilateral contract, by contrast, gives rise to obligations on one side only. Thus "I will give you £100 if you run a marathon" gives rise to a legal duty on the maker of the statement (the promisor) to pay the money if the race is run, whilst the person to whom the statement is made (the promisee) is under no obligation to run in the first place.

Now decide if the contracts listed below are unilateral or bilateral.

1.  A broker offers a trip to Hawaii to any salesperson who sells $1 million of property during the month.
unilateral
bilateral
(1 p.)



2.  A contract for the sale of a home, the buyer promises to pay the seller $200,000 in exchange for the seller's promise to deliver title to the property.
unilateral
bilateral
(1 p.)



3.  John promises Mary to pay her € 50 if she finds his dog.
unilateral
bilateral
(1 p.)



4.  Someone offered to drive you to work on Mondays and Tuesdays in exchange for your promise to return the favour on Wednesdays and Thursdays.
unilateral
bilateral
(1 p.)



5.  I will pay you $1,000 if you bring my car from Cleveland to San Francisco.
unilateral
bilateral
(1 p.)



6.  Chris promises to sell Joe a car for $1000 and Joe promises to pay $1000 for the car.
unilateral
bilateral
(1 p.)