They are: (1) Consent of a minor or a person with an unhealthy mind. [Sec.(11)] (2) Agreement the consideration or object of which is unlawful [§23)] para. (3) Agreement concluded as a result of a bilateral factual error in the agreement[§20)] (4) Agreement the consideration or object of which is partially unlawful and the illegal part cannot be dissociated from the legal part [§24)] (5) Agreement concluded. Without consideration. [Sec.(25)] (6) Agreement to Restrict Marriage [§ 26]] (7) Agreement to Restrict Trade [§27)] (8) Agreement to Limit Legal Proceedings [§28]] (9) Agreements; The meaning of which is uncertain [§29]] (10) Paris Agreements [§30]] (11) Agreements that depend on impossible events [§36]] (12) Agreements on impossible acts [§56)] All parties should agree and abide by the terms of an offer.