How would the courts deal with a clause in a contract for the sale of a horse which promised the seller an

• It would be enforced in the same way as any other clause.

• It would be held as illegal as a gaming contract.

• The clause would probably be held unenforceable due to lack of certainty.

• The entire contract would be held as unenforceable.

• additional ?5 fee if the horse proved to be lucky?