Russia
Article 178. Invalidity of Transaction Concluded under Influence of Delusion
1. A transaction concluded under the influence of delusion having material significance may be deemed by a court to be invalid upon the suit of the party which acted under the influence of delusion.
Delusion as to the nature of a transaction, the identity, or such qualities of its subject which considerably reduce the possibility of using it for its purpose shall have material significance. Delusion as to the motives of a transaction shall not have material significance.
2. If a transaction is deemed to be invalid as concluded under the influence of delusion, the rules provided for by Article 167(2) of this Code shall apply respectively.
In addition, the party upon whose suit the transaction was deemed to be invalid shall have the right to demand from the other party compensation for real damage caused to it if it is proved that the delusion arose through the fault of the other party. If it not proved, the party at whose suit the transaction was deemed to be invalid shall be obliged to compensate the other party at its demand for real damage caused to it even if the delusion arose through circumstances beyond the control of the deluded party.