## Facts

- Roscorla purchased a horse from Thomas; the sale constituted the initial transaction between the parties.
- After the sale was concluded, Thomas assured Roscorla that the horse was sound, free from vice, and of good quality.
- The horse was later discovered to have a vicious temperament, contrary to Thomas’s assurance.
- Roscorla brought a claim for breach of contract based on the post-sale statement about the horse’s condition.
- The central question was whether Thomas’s assurance, made after the sale, formed a binding contractual warranty supported by valid consideration.

## Issues

1. Whether a promise made after the completion of a contractual transaction (the sale of the horse) is enforceable.
2. Whether the purchaser’s prior act of buying the horse constitutes valid consideration for the seller’s subsequent warranty regarding the horse’s quality.

## Decision

- The Court of Queen’s Bench held that the only consideration provided by Roscorla, the purchase of the horse, was completed before the subsequent promise was made.
- The court ruled that past consideration, such as an act completed prior to a later promise, cannot support that promise.
- The warranty given after the sale was not supported by new or contemporaneous consideration and was therefore unenforceable.
- The only promise implied by the original sale was the transfer of ownership, not the subsequent assurance of quality.

## Legal Principles

- In contract law, consideration must be given in exchange for a promise; past acts or benefits do not qualify as good consideration for a subsequent promise.
- A promise made after a completed transaction, without new consideration, is deemed gratuitous and unenforceable.
- The general rule from this case is subject to limited exceptions, such as where the prior act was performed at the request of the promisor and a later promise was understood at the outset to be forthcoming, as established in cases like Lampleigh v Brathwait (1615).
- The decision in Roscorla v Thomas maintains that consideration and a legal promise must be concurrent or mutually exchanged.

## Conclusion

Roscorla v Thomas established that past consideration is insufficient to support a subsequent promise, reinforcing the requirement that consideration must be contemporaneous with, or given in exchange for, the promise in order for it to be enforceable in contract law.


Roscorla v Thomas (1842) 3 QB 234