It will therefore be uneven to think of an agreement without compensation. Therefore, we can simply summarize the importance of the consideration: except in certain cases, a contract cannot be envisaged without consideration and, if concluded, it is free from any legal obligation. Verdict: “Rogata” can exonerate him and then sue “Voatka” to recover the amount. It is therefore a valid agreement. (3) Agreement concluded as a result of a bilateral factual error essential to the agreement [§20]] 4.1 Validity of an agreement without consideration: an agreement concluded without consideration is not valid unless an undertaking to compensate all or part of the voluntary service of the promiser is enforceable. In other words, the promise to pay for past voluntary service is binding. .