This questions deals with about consideration, which is another requirement of the contract.

Consideration is defined as “it

may consist of either in some right, interest profit or benefit accruing to the one party, or some forbearance, detriment, loss if
responsibility given, suffered or undertaken by the other”(Curie v Misa). Therefore issues in this question is as follows: Was
the Greta’s consideration of pre-existing contractual obligation is good consideration? Was Felix part payment of debt
constitutes as a good consideration?

Promises are only enforceable if they are supported by consideration. Consideration is that which is given in return for a
promise which has sufficient value in law. Consideration cannot be past, nor can the performance of an existing contractual or
public duty provide consideration for a fresh promise. Consideration must be given in return for the promise or act of the
other party. If there is no consideration, then the promise is a gratuitous one which may impose a moral but not a legal
obligation. In contract law, there are two types of consideration; Executed Consideration which refers to a promise made in
exchange for an act that has already been completed. In other words, the act that forms the consideration has already taken
place before the contract is formed. Executory Consideration this involves a promise for a future act or performance. The
consideration in this case is not yet completed at the time the contract is formed; it is a promise to do something in the future.
Consideration is a crucial element in the formation of a valid contract, as it ensures that both parties provide something of
value in the exchange. When framing a problem question in contract law, it's important to analyze whether the consideration
offered is executed or executory, as this can affect the enforceability of the contract.

According to the general rule of performance of an existing contractual obligation is not the good consideration (Stilk v
Myrick), but if the promisor has to perform something extra than his existing contractual duty than this fall under the
exception to this general rule. As from the facts of the question is clear that Greta has to some extra work regarding making
the swimming pool so this situation fall in the exception as discussed above, so here the William v Roffey bros will apply here,
which indicates that as the promise from prince Felix to make extra bonus was not been made under the duress and the
prince Felix may receive some benefits from Greta’s work like she has to work hard to complete the swimming pool on the
decided date of the contract and Felix has been avoided by the trouble and expense of engaging of the other people to work,
so here the necessary consideration is provided by Prince Felix. So the requirements of consideration is valid in this contract
and the court may enforce Prince Felix to pay Greta the money which was promised by him earlier. Here one might argue that
Greta hasn’t provide any consideration so the promise is not enforceable, but this argument might prove wrong as it is clear
from the fact of the question that she has faced some difficulties in the commence of the work so she has to work harder than
she has anticipated (Hartley v Ponsonby) this shows that the consideration is also provided from Greta’s side so this makes the
contract enforceable.

In the William v Roffey Bros case, the Court of Appeal established the principle of "practical benefit" as a form of
consideration. This principle allows for the enforcement of a promise to pay extra money to a party already under contract if
the promisor obtains a practical benefit from that promise. The court held that the promise could be legally binding even
though the promisee was already under an existing contractual duty.

Prince Felix's inability to make the final payment due to the extensive damage to his palace may raise the defense of
frustration of contract. Frustration occurs when unforeseen events make it impossible or radically different from what was
originally intended to perform the contract. In this context, Prince Felix could argue that the damage to his palace was an
unforeseen event that made it impossible for him to pay the original contract amount. However, frustration is a high threshold
in contract law, and it must truly render performance impossible, not just more difficult or financially burdensome. Whether
or not the court would accept this as a valid defense depends on the specific facts of the case and the degree of
impracticability caused by the damage.

Hans initially offered to reduce the final installment to £2 million. When Prince Felix accepted this reduced offer, it formed a
contract modification. Generally, once an offer is made and accepted, it can form a legally binding contract, and the parties are
bound by the modified terms. In the context of William v Roffey Bros, if Prince Felix can demonstrate that Hans obtained a
practical benefit from the reduced offer (such as avoiding a potential breach of contract), the principle of practical benefit as a
form of consideration may apply. This means that the reduced promise to pay £2 million could be legally binding, even though
it was less than the original contract amount.

Consideration is an essential element of a contract, and it generally refers to something of value exchanged between the
parties. In William v Roffey Bros, the consideration was the practical benefit gained by the promisor (Roffey Bros) in getting the
promisee (Williams) to perform their contractual duty. In both the payment dispute and the reduced offer scenarios,
consideration is present. In the payment dispute, the consideration could be the avoidance of a potential breach of contract or
the practical benefit Hans gained from Prince Felix's acceptance of the reduced amount.

At the end, Based on the principles established in William v Roffey Bros, it appears that Greta may have a valid claim for the
additional £100,000. Prince Felix's agreement to pay extra in light of unforeseen difficulties and the practical benefit he gained
from the timely completion of the pool could constitute valid consideration. Therefore, it would be advisable for Prince Felix to
reconsider his position and, if appropriate, fulfill his agreement to pay the extra amount. In Prince Felix's situation, both the
part payment dispute and the reduced offer scenario involve complex legal considerations related to contract law. While the
William v Roffey Bros principle of practical benefit provides a framework for analyzing these issues, the specific outcome will
depend on the unique facts and circumstances of the case. Rather here the discretion is upon the courts Certainly, in cases
involving the practical benefit doctrine, it ultimately falls within the court's discretion to determine which party is deserving of
its application. This decision hinges on the evidence presented by both legal counsels, as they must establish how the promise
provided a practical benefit to the promisor and influenced the performance of the promisee. The court will weigh these
factors to determine the enforceability of the promise in light of the principle established in William v Roffey Bros Ltd (1991).