Binding Vow

Contracts (aka "bindings" or "cursed restrictions") are formal agreements between shamans and themselves or others. They are very important in the Jujutsu Kaisen universe, being "one of the essential tenets of sorcery".

Little is known about contracts, but they appear to operate similarly to conditions in Nen. The shaman or shamans involved will sacrifice something for a gain. There appears to be no limit to what can be contracted, and it is at this stage unclear how specifically the contract must be adhered to and the level of interpretation open to the parties involved.

Contracts with Oneself
It is unknown how a contract with oneself can be made. Contracts made with oneself are much more common and a lot easier to make than contracts with others. The penalty for breaking a contract made with oneself is that the gain made as a result of the contract is lost or nullified. Examples of contracts with oneself are as follows:
 * "Showing One's Cards": A contract where the shaman party to the contract states their cursed technique abilities to their opponent. In exchange for the opponent's knowledge of their abilities, the shaman gains increased power, although it is unclear the size of the increase. Used by Kento Nanami and Hanami.
 * "Overtime": A contract where the shaman party to the contract limits their cursed energy and cursed technique abilities for a set amount of time. Once this time has passed, the shaman is able to significantly increase their cursed energy and cursed technique abilities. Used by Kento Nanami.

Contracts with Others
Even less is known about contracts with others. It is unclear how they can be made, but some level of negotiation is required, and both parties must accept the terms, although this can be conditional. The penalty for breaking a contract with others is unknown at this stage.

Examples of contracts with others are as follows:
 * A contract between Yuji Itadori and Sukuna for Yuji's revival.  Sukuna proposed a contract where he would revive Yuji's body in exchange for being allowed to take over Yuji's body for 1 minute when Yuji said a word, with the guarantee he would not kill or hurt anyone during that minute but the condition that Yuji would forget about this contract when he was revived. Yuji proposed that they have a fight to the death: if he wins, then Sukuna will revive him without the contract, and if Sukuna wins, then Yuji will agree to the contract. Sukuna then wins and Yuji is revived, presumably enacting the contract.
 * A contract between Mahito, Suguru Geto , and Kokichi Muta for Muta to act as a double agent for Mahito and Geto. Mahito and Geto agreed to heal Muta's body with Mahito's cursed technique in exchange for cooperation and information, on the condition that Mahito and Geto would not "lay a finger on anyone from Kyoto Jujutsu High." It is alleged by Muta that this contract is broken, but Mahito rebuts this point by stating that Hanami actually was the one who hurt the students from the Kyoto College. Muta is transformed by Mahito's cursed technique after acting as a double agent for presumably some time, which brings the contract to an end, although it is unclear whether there was a breach.

Heavenly Restriction
It is debated whether Heavenly Restriction can be considered a contract or not. See Heavenly Restriction for further information.