# Civil legal doctrines and principles list Arm's length principle (contract law) - the parties of a transaction must be independent and on equal footing Assumption of risk (tort law) - a defense that a defendant is not liable for risks that the plaintiff knowingly ignored, can be express or implied Attractive nuisance doctrine (tort law) - a landowner may be held liable for injuries to children trespassing on their land if the injury is caused by an object on the land that's likely to attract children Balance of probabilities - a legal standard of proof commonly used in civil court that indicates that the ruling will decide based on what party's claim is most probable when considering all the factors, in contrast with reasonable doubt Blue pencil doctrine (contract law) - if a [contract](people-contracts.md) has unenforceable components, its enforceable parts are still legally valid Caveat actor - Latin for "let the doer beware", the person performing the action is responsible for their action. Caveat emptor (contract law) - Latin for "let the buyer beware", the buyer must be aware of details pertaining to whom they're buying from and the product they're buying Caveat lector (contract law) - Latin for "let the reader beware", the reader should take careful note of a text's contents and undertake due diligence on whether the contents are accurate, reliable, relevant, etc. Caveat venditor (contract law) - Latin for "let the seller beware", the seller must be aware of details pertaining to whom they're selling to and why Clausula rebus sic stantibus (contract law) - Latin for "as things stand", a contract or treaty becomes inapplicable because of a material change in circumstances, counter-balances pacta sunt servanda Clayton's case - debts to a bank must be paid in the order they were incurred Collateral source rule (common law) - evidence that the plaintiff/victim has received payment from a source that wasn't directly from the defendant is inadmissible, which allows for double recovery against the defendant (e.g., medical insurance paying a bill doesn't count toward the plaintiff's recovery) Comparative negligence (tort law) - aka "non-absolute contributory negligence", the fault/negligence of each party involved is based on the percentage responsibility for the event, a frequent concept in [insurance](money-insurance.md) Concurrent delay doctrine (contract law) - when both parties to a contract cause delays, neither party can recover damages for the period of time when both parties were at fault Contra proferentem - Latin for "against the offeror", aka "interpretation against the draftsman", when a promise, agreement, or term is ambiguous the preferred meaning should be the one that works against the interests of the party who provided the wording Contributory negligence (tort law) - the defense completely bars plaintiffs from any recovery if they contribute to their injury through their negligence - Last clear chance doctrine - in tort law when using contributory negligence, a negligent plaintiff can still recover if they can show the defendant had the "last clear chance" to avoid the accident Corporate opportunity (trust law) - directors, officers, and controlling shareholders of a corporation must not take any business opportunity for themselves which could benefit their corporation Crumbling skull rule (tort law) - when a plaintiff had a condition or injury that predates the tort and would have naturally deteriorated or worsened over time (e.g., a crumbling skull) the defendant is not responsible for that part of the condition or injury Dumpor's case rule (property law) - if a landlord consents to assigning a tenant's interest in a lease, they implicitly consent to all future assignments by the assignee Duty of care (tort law) - an individual must legally adhere to a set standard of practices to not risk harming others Duty to rescue (tort law) - a party can be held liable for failing to come to the rescue of another party who could face potential injury or death without being rescued Eggshell skull (tort law) - the unexpected frailty of the injured person is not a valid defense to the seriousness of any injury caused to them Estoppel - if a person says something, they can't use the law to redact their word Ex turpi causa non oritur actio - Latin for "from a dishonorable cause, an action does not arise", aka "illegality defense", a plaintiff cannot pursue legal action if they themselves performed something illegal in the event of that situation happening Fireman's rule (tort law) - aka "firefighter's rule", public safety officials like firefighters and police (and occasionally *all* public safety professionals) are not responsible for damages that occur in the course of their duties, even in cases of clear negligence by other parties Four corners rule (contract/inheritance law) - If terms are ambiguous, the court must rely solely on the written instrument and can't consider extraneous evidence Fundamental breach - while most contract breaches nullify a contract in part, a breach can be so bad it nullifies a contract fully Hotchpot rule - sometimes blending, combining or offsetting property (typically gifts) can ensure equality of a later division of property, most commonly in divorce proceedings Intention to create legal relations (contract law) - aka "intention to be legally bound", a court should presume parties to an agreement wish for that agreement to be legally binding, and it's only legally enforceable if they intended it to be Last shot rule (contract law) - a party will implicitly accept a counter-offer by indicating no objection to it, named after sellers normally "firing the last shot" by sending the final form in a negotiation Laesio enormis (contract law) - a contracting party can rescind an agreement if the price of an exchange is less than 1/2 or 1/3 of its actual value Locus standi - Latin for "standing location", aka standing, where a party seeking a legal remedy must demonstrate that they are sufficiently connected to a law they're claiming was violated Mirror image rule - aka "unequivocal and absolute acceptance requirement", an offer must be accepted exactly with no modifications, and an attempt to accept the offer on different terms instead creates a counter-offer Parol evidence rule (contract law) - if a contract is written, then verbal agreements that had been made that weren't captured in writing cannot be submitted as evidence Posting rule (contract law) - a contract is typically bound at the date it was signed, but is only valid after the other party receives their expected goods Pottery Barn rule (contract law) - if someone breaks an object on display for sale, they have created a contract to purchase it Pre-existing duty rule (contract law) - performing a duty that existed before engaging in a contract doesn't count as the duty that could form that contract Privity of contract (contract law) - a contract can't confer rights or impose obligations on anyone who isn't a party to that contract Proper law - the choice of law is a distinctive stage when there's a conflict of applicable laws, and the state has regulations to determine which laws will apply Res ipsa loquitur (tort law) - Latin for "the thing speaks for itself", a court can infer negligence from the very nature of an accident or injury even when there's no direct evidence of the defendant's behavior Restraints of trade (competition law) - unless the law has regulations directly overseeing a contract, everyone should have the freedom to regulate their mode of making agreements according to their discretion and choice Rule in Dumpor's Case - once a landlord consents to assigning a tenant to a lease, they implicitly consent to all future assignments by the that tenant Subrogation - a third party (e.g., second creditor, insurance company) can assume another party's legal right to collect a debt or damages Substantial performance (contract law) - a court can imply a partial or substantially similar performance to stand in for a contract's specified performance, an alternative principle to the perfect tender rule Unconscionability - a contract that's *extremely* one-sided is unethical to enforce ## USA Assumption of risk (tort law) - a plaintiff's right to recovery is reduced or barred against a negligent tortfeasor if the defendant can demonstrate the plaintiff voluntarily assumed the risks at issue inherent to their dangerous activity Baseball rule - a baseball team isn't responsible for injuries caused by a foul ball if they put protected seating for the most likely areas where a foul ball would travel Calculus of negligence - aka "the Hand Rule", the owner's duty to provide against an injury is based on (1) the chances an injury might happen, (2) the severity of that injury, and (3) the burden was sufficient for taking precautions against risks Faithless servant - in New York, employees who act unfaithfully toward their employers must give up all compensation they've received during that period of disloyalty Learned intermediary - a manufacturer of a product has fulfilled its duty of care when it has provided all the necessary information to a "learned intermediary" who then interacts with the consumer of a product, primarily used by pharmaceutical and medical device manufacturers to defend tort suits Rescue doctrine (tort law) - if the defendant creates a circumstance that places the victim in danger, they're not only liable for the harm caused to the victim but also harm caused to anyone injured while trying to rescue them Substantial truth - a statement can't be held as slander or libel if the statement is true but has "slight inaccuracies of expression" Valid when made - if the terms of a loan are valid at their creation, they're still valid if the lienholder is sold or assigned to another party ## UK Common employment (tort law) - when workers injure their fellow workers, the company who employs them is *not* responsible Indoor management rule (company law) - aka "Rule in Turquand's Case", people transacting with companies are entitled to assume internal company rules are honored, even when they're not Non-derogation from grants doctrine (property law) - a seller of realty or goods can't take any action that will lessen the buyer's value of the thing sold ## Germany Abstraction principle - the buyer and seller in a [business contract](people-contracts.md) don't necessarily own the payment or the object after the transfer, and it requires 3 contracts: 1. the contract of sale itself that obligates the seller to transfer ownership of the product to the buyer and the buyer to pay the price 2. a contract that transfers ownership of the product to the buyer, fulfilling the seller's obligation 3. a contract that transfers ownership of the money from the buyer to the seller, fulfilling the buyer's obligation