15.12 When the Contract becomes Void

Specific goods perishing before contract — void (the parties contracted about nothing — mutual mistake/impossibility); Specific goods perishing after contract but before risk passes — the agreement avoided (frustration — Unit 6's general doctrine applied); Unascertained/future goods' failure — never coming into existence; Illegality — prohibited goods, banned trades, criminal purpose; Mistake as to identity or existence of the subject-matter; incapacity (the general vitiators); Contingency's failure — contingent goods whose event never occurs (Unit 8's voidness). Exam Focus Long questions: "Explain the implied conditions and warranties in a sale of goods, with caveat emptor's exceptions." / "Discuss the rules by which property and risk pass in a sale of goods, including nemo dat and its exceptions." / "What are the rights of an unpaid seller against the goods and against the buyer personally?" Short questions: sale vs. agreement to sell; the goods' three classes; stoppage in transit; sale on approval; market-difference damages; res perit domino; the retention-of- title clause. Trick areas: (i) in a sale, risk follows property — not possession or payment; (ii) the condition's breach allows rejection; the warranty's only damages — but the buyer may elect down (condition treated as warranty), never up; (iii) nemo dat protects the owner — the five exceptions protect commerce; (iv) stoppage in transit needs the buyer's insolvency — mere non-payment is…