The doctrine of impracticability in the common law of contracts excuses performance of a duty, where the said duty has become unfeasibly difficult or expensive for the party who was to perform.

Impracticability is similar in some respects to the doctrine of impossibility because it is triggered by the occurrence of a condition which prevents one party from fulfilling the contract. The major difference between the two doctrines is that while impossibility excuses performance where the contractual duty cannot physically be performed, the doctrine of impracticability comes into play where performance is still physically possible, but would be extremely burdensome for the party whose performance is due. Thus, impossibility is an objective condition, whereas impracticability is a subjective condition for a court to determine.

Typically, the test U.S. courts use for impracticability is as follows (with a few variations among different jurisdictions):

1.    There must be an occurrence of a condition, the nonoccurrence of which was a basic assumption of the contract.

2.    The occurrence must make performance extremely expensive or difficult.

3.    This difficulty was not anticipated by the parties to the contract (note: some jurisdictions require that there be no measure within the contract itself to allocate risk between the parties).

An illegal agreement under the common law of contract, is one that the court will not enforce because the purpose of the agreement is to achieve an illegal end. The illegal end must result from performance of the contract itself. The classic example of such an agreement is a contract for murder.

The illegality of a contract depends on (1) the law of the country governing the contract, and (2) the law of the place of performance. Different rules will apply depending on the law of the relevant country(ies).

However, a contract that requires only legal performance on the part of each party, such as the sale of packs of cards to a known gambler, where gambling is illegal, will nonetheless be enforceable. A contract directly linked to the gambling act itself, such as paying off gambling debts (see proximate cause), however, will not meet the legal standards of enforceability. Therefore, an employment contract between a blackjack dealer and a speakeasy manager, is an example of an illegal agreement and the employee has no valid claim to his anticipated wages if gambling is illegal under that jurisdiction.

Clean hands, sometimes called the clean hands doctrine, unclean hands doctrine, or dirty hands doctrine, is an equitable defense in which the defendant argues that the plaintiff is not entitled to obtain an equitable remedy because the plaintiff is acting unethically or has acted in bad faith with respect to the subject of the complaint—that is, with "unclean hands". The defendant has the burden of proof to show the plaintiff is not acting in good faith. The doctrine is often stated as "those seeking equity must do equity" or "equity must come with clean hands". This is a matter of protocol, characterized by A P Herbert in Uncommon Law by his fictional Judge Mildew saying (as Herbert says, "less elegantly"), "A dirty dog will not have justice by the court".

A defendant's unclean hands can also be claimed and proven by the plaintiff to claim other equitable remedies and to prevent that defendant from asserting equitable affirmative defenses. In other words, 'unclean hands' can be used offensively by the plaintiff as well as defensively by the defendant. Historically, the doctrine of unclean hands can be traced as far back as the Fourth Lateran Council.

"He who comes into equity must come with clean hands" is an equitable maxim in English law.

Trover cases in the United States.

Trover is the name of the action which lay, at common law, for the recovery of damages for the conversion of personal property in his possession, usually involving chattels held in bailment. Although the old forms of action have been abolished or disappeared under modern civil procedure in the United States, the common law action for conversion still exists in fact, if not in form. (Extensive case law is reviewed.) 

A person who purchases personal property from one not authorized to sell the chattel may be held liable for the conversion of the article. This is regardless of the fact that the purchaser was honestly mistaken, or acted innocently, in good faith and without knowledge of the seller's lack of authority to make the sale. This rule also holds in cases where the purchaser takes possession of the goods, mixes them with his own property, holds them to his own use, refuses to surrender possession on demand, disposes of the goods to a third person by sale, lease or bailment or in general exercises rights of ownership as to the property purchased in denial of the real owner's rights after knowledge of the rights of the true owner.

Deaderick v Oulds, 1887.

In the 1887 case of Deaderick v Oulds, the Supreme Court of Tennessee ruled on a case of trover. The defendant, Oulds, cut 800 walnut logs, branded them with the letter "D", then proceeded to float them down a river with the intention of recovering them downstream. Sometime later, Oulds found an unmarked log among his other marked logs which had peculiar cracks at one end. He floated the unmarked log down the river, and it washed up on an island owned by the plaintiff, Deaderick, who then claimed the log as his in trover or replevin. The Tennessee court quoted the English case of Bridges v Hawkesworth where the plaintiff, being in the shop of the defendant, picked up a parcel containing bank notes. The defendant, at the request of the finder, took charge of the notes, to hold for the owner. After three years, no one had come forth to claim them. The defendant shop owner refused to deliver them to the plaintiff. The court held the defendant shop owner liable in trover for the notes.

The Tennessee Supreme Court observed it is essential in cases of trover, that the property must be found; it must at the time when the finder came upon it, to have been in such a situation as to clearly indicate that it was lost. It cannot have been placed there by the original owner who lost it by carelessness or forgetfulness, where it was later found by someone else. In such cases, the owner of the premises where the property is found is treated as a quasi-bailee (i.e. he holds the property for the original owner), and he may maintain trover against the finder. Since the log was not intentionally laid by the (unknown) owner on the land of the plaintiff (Deaderick), and hence he was not a quasi-bailee for the owner, he cannot hold against the superior right of the defendant (Oulds) arising out of his prior possession and earlier finding of the log. Judgment for ownership of the log was to the defendant Oulds.

Tax collection and examinations

Tax returns

Individuals (with income above a minimum level), corporations, partnerships, estates, and trusts must file annual reports, called tax returns, with federal and appropriate state tax authorities. These returns vary greatly in complexity level depending on the type of filer and complexity of their affairs. On the return, the taxpayer reports income and deductions, calculates the amount of tax owed, reports payments and credits, and calculates the balance due.

Federal individual, estate, and trust income tax returns are due by April 15 for most taxpayers. Corporate and partnership federal returns are due two and one half months following the corporation's year end. Tax exempt entity returns are due four and one half months following the entity's year end. All federal returns may be extended, with most extensions available upon merely filing a single page form. Due dates and extension provisions for state and local income tax returns vary.

Income tax returns generally consist of the basic form with attached forms and schedules. Several forms are available for individuals and corporations, depending on complexity and nature of the taxpayer's affairs. Many individuals are able to use the one page Form 1040-EZ, which requires no attachments except wage statements from employers (Forms W-2). Individuals claiming itemized deductions must complete Schedule A. Similar schedules apply for interest (B), dividends (B), business income (C), capital gains (D), farm income (F), and self-employment tax (SE). All taxpayers must file those forms for credits, depreciation, AMT, and other items that apply to them.

Electronic filing of tax returns may be done for taxpayers by registered tax preparers.

If a taxpayer discovers an error on a return, or determines that tax for a year should be different, the taxpayer should file an amended return. These returns constitute claims for refund if taxes are determined to have been overpaid.

The IRS, state, and local tax authorities may examine a tax return and propose changes. Changes to tax returns may be made with minimal advance involvement by taxpayers, such as changes to wage or dividend income to correct errors. Other examination of returns may require extensive taxpayer involvement, such as an audit by the IRS. These audits often require that taxpayers provide the IRS or other tax authority access to records of income and deductions. Audits of businesses are usually conducted by IRS personnel at the business location.

Changes to returns are subject to appeal by the taxpayer, including going to court. IRS changes are often first issued as proposed adjustments. The taxpayer may agree to the proposal, or may advise the IRS why it disagrees. Proposed adjustments are often resolved by the IRS and taxpayer agreeing to what the adjustment should be. For those adjustments to which agreement is not reached, the IRS issues a 30-day letter advising of the adjustment. The taxpayer may appeal this preliminary assessment within 30 days within the IRS.

The Appeals Division reviews the IRS field team determination and taxpayer arguments, and often proposes a solution that the IRS team and the taxpayer find acceptable. Where agreement is still not reached, the IRS issues an assessment as a notice of deficiency or 90-day letter. The taxpayer then has three choices: file suit in United States Tax Court without paying the tax, pay the tax and sue for refund in regular court, or pay the tax and be done. Recourse to court can be costly and time-consuming, but is often successful.

A license is an official permission or permit to do, use, or own something (as well as the document of that permission or permit).

A license is granted by a party (licensor) to another party (licensee) as an element of an agreement between those parties. In the case of a license issued by a government, the license is obtained by applying for it. In the case of a private party, it is by a specific agreement, usually in writing (such as a lease or other contract). The simplest definition is "A license is a promise not to sue," because a license usually either permits the licensed party to engage in an activity which is illegal, and subject to prosecution, without the license (for example, fishing, driving an automobile, or operating a broadcast radio or television station), or it permits the licensed party to do something that would violate the rights of the licensing party (for example, make copies of a copyrighted work), which, without the license, the licensed party could be sued, civilly, criminally, or both.

In particular, a license may be issued by authorities, to allow an activity that would otherwise be forbidden. It may require paying a fee or proving a capability (or both). The requirement may also serve to keep the authorities informed on a type of activity, and to give them the opportunity to set conditions and limitations.

A licensor may grant a license under intellectual property laws to authorize a use (such as copying software or using a patented invention) to a licensee, sparing the licensee from a claim of infringement brought by the licensor. A license under intellectual property commonly has several components beyond the grant itself, including a term, territory, renewal provisions, and other limitations deemed vital to the licensor.

Term: many licenses are valid for a particular length of time. This protects the licensor should the value of the license increase, or market conditions change. It also preserves enforceability by ensuring that no license extends beyond the term of the agreement.

Territory: a license may stipulate what territory the rights pertain to. For example, a license with a territory limited to "North America" (Mexico, United States and Canada) would not permit a licensee any protection from actions for use in Japan.

Again, a shorthand definition of license is "a promise by the licensor not to sue the licensee". That means without a license any use or exploitation of intellectual property by a third party would amount to copying or infringement. Such copying would be improper and could, by using the legal system, be stopped if the intellectual property owner wanted to do so.

Intellectual property licensing plays a major role in business, academia and broadcasting. Business practices such as franchising, technology transfer, publication and character merchandising entirely depend on the licensing of intellectual property. Land licensing (proprietary licensing) and IP licensing.

An inchoate offense, preliminary crime, inchoate crime or incomplete crime is a crime of preparing for or seeking to commit another crime. The most common example of an inchoate offense is "attempt". "Inchoate offense" has been defined as the following: "Conduct deemed criminal without actual harm being done, provided that the harm that would have occurred is one the law tries to prevent."

Intent.

Every inchoate crime or offense must have the mens rea of intent or of recklessness, typically intent. Absent a specific law, an inchoate offense requires that the defendant have the specific intent to commit the underlying crime. For example, for a defendant to be guilty of the inchoate crime of solicitation of murder, he or she must have intended for a person to die.

Attempt, conspiracy, and solicitation all require mens rea.

On the other hand, committing an offense under the US Racketeer Influenced and Corrupt Organizations Act merely requires "knowing", that is, recklessness. Facilitation also requires "believing", yet another way of saying reckless.

Intent may be distinguished from recklessness and criminal negligence as a higher mens rea.

Proof of intent.

Specific intent may be inferred from circumstances. It may be proven by the doctrine of "dangerous proximity", while the Model Penal Code requires a "substantial step in a course of conduct".

Merger doctrine.

The doctrine of merger has been abandoned in many jurisdictions in cases involving a conspiracy, allowing an accused to be convicted of both conspiracy and the principal offense. However, an accused cannot be convicted of either attempt or solicitation and the principal offense.

In contract law, impossibility is an excuse for the nonperformance of duties under a contract, based on a change in circumstances (or the discovery of preexisting circumstances), the nonoccurrence of which was an underlying assumption of the contract, that makes performance of the contract literally impossible.

For example, if Ebenezer contracts to pay Erasmus £100 to paint his house on October 1, but the house burns to the ground before the end of September, Ebenezer is excused from his duty to pay Erasmus the £100, and Erasmus is excused from his duty to paint Ebenezer's house; however, Erasmus may still be able to sue under the theory of unjust enrichment for the value of any benefit he conferred on Ebenezer before his house burned down.

The parties to a contract may choose to ignore impossibility by inserting a hell or high water clause, which mandates that payments continue even if completion of the contract becomes physically impossible.

In common law, for the defense of "impossibility" to be raised performance must not merely be difficult or unexpectedly costly for one party, there must be no way for it to actually be accomplished; however, it is beginning to be recognized that "impossibility" under this doctrine can also exist when the contemplated performance can be done but only at an excessive and unreasonable cost, i.e., commercial impracticability. On the other hand, some sources see "impossibility" and impracticability as being related but separate defenses.

The English case that established the doctrine of impossibility at common law is Taylor v Caldwell.

Frustration of purpose, in law, is a defense to enforcement of a contract. Frustration of purpose occurs when an unforeseen event undermines a party's principal purpose for entering into a contract such that the performance of the contract is radically different from performance of the contract that was originally contemplated by both parties, and both parties knew of the principal purpose at the time the contract was made. Despite frequently arising as a result of government action, any third party or even nature can frustrate a contracting party's primary purpose for entering into the contract. The concept is also called commercial frustration.

For example, if Joe gets a mortgage for a new home, suppose after three years, the home is destroyed, through no fault of Joe's. Without a hell or high water clause, Joe might be exempt from the remainder of the mortgage, as the principal purpose of the contract, to have a home to live in, has been compromised. However, he might still have a foreclosure on his credit rating.

Frustration of purpose is often confused with the closely related doctrine of impossibility. The distinction is that impossibility concerns the duties specified in the contract, but frustration of purpose concerns the reason a party entered into the contract. An example is if entrepreneur Emily leases space from landlord Larry so that she can open a restaurant that serves only Tibetan Speckled Lizard meat. If the city rezones the property to forbid commercial uses or if the property is destroyed by a tornado, both Larry and Emily are excused from performing the contract by impossibility.

Trover (/ˈtroʊvər/) is a form of lawsuit in common-law countries for recovery of damages for wrongful taking of personal property. Trover belongs to a series of remedies for such wrongful taking, its distinctive feature being recovery only for the value of whatever was taken, not for the recovery of the property itself (see replevin).

Overview.

Although actions in trover can be traced to the time of Bracton, and later Edward I of England, it became more clearly defined later during the reign of Henry VI of England, 1422 thru 1461 and 1470 thru 1471. Action in trover became a mature legal doctrine during the reign of Elizabeth I of England, 1558–1603.

Early trover cases involved the keeping or taking of a bailment by the bailee (the person charged to hold the property with "ordinary care"). Others concerned the use of lost chattels found by another and determining who was the real owner. Early on, there was difficulty in dealing with situations where chattels held by a bailee were used by a third party. Examples could be sheep, horses, farm goods, grains or other chattels left in the care of a person who was required to exercise ordinary care. If negligence led to damages, an action could be had. A third person might use the chattel, returning it in a damaged condition. The early common law had some difficulty in dealing with this kind of situation. This led to expansions of actions in trover.

The theory of trover was that the defendant, by "converting" the chattel to his own use, had appropriated the plaintiff's property, for which he was required to make compensation. The plaintiff was not required to accept the chattel when it was tendered back to him. He could recover damages for the full value of the chattel at the time and place of conversion. The effect was that the defendant was compelled to buy the chattel at a forced sale, carried out by means of an action in trover.

Trover actions frequently concerned the finding of lost property. It could also involve cargo on ships, such as those lost at sea and later found. Trover often involved cases in which the only "most correct" owner could be determined. For instance, if an envelope of bank notes or currency were to be found, the court would attempt to identify the true owner, but this would often prove to be impossible. In that case, the finder would be the next best owner and be considered the rightful possessor. Trover cases have been described as "finders keepers, losers weepers" cases.

Trover damages came to be measured by the market value of the object, not necessarily its replacement cost if it were new. Sometimes, compensation for deprivation of use and compensation for other losses naturally and proximately caused by the wrongful taking could be added. Case law results are mixed. The plaintiff could also recover interest that would have been earned by the money value of the object and any expense (except attorney's fees) incurred in attempting to recover the object. If the taker sold the object for more than its market value, the plaintiff could receive the higher price. However, selling the chattel could change the action to that of a true conversion which was a form of theft. If the taker had made improvements on the object (for example, repainted it), the value of such improvements are not deducted from the plaintiff's recovery unless the taking was by mistake.

Taxable income.

Income tax is imposed as a tax rate times taxable income. Taxable income is defined as gross income less allowable deductions. Taxable income as determined for federal tax purposes may be modified for state tax purposes.

Gross income.

The Internal Revenue Code states that "gross income means all income from whatever source derived," and gives specific examples. Gross income is not limited to cash received, but "includes income realized in any form, whether money, property, or services." Gross income includes wages and tips, fees for performing services, gain from sale of inventory or other property, interest, dividends, rents, royalties, pensions, alimony, and many other types of income. Items must be included in income when received or accrued. The amount included is the amount the taxpayer is entitled to receive. Gains on property are the gross proceeds less amounts returned, cost of goods sold, or tax basis of property sold.

Certain types of income are exempt from income tax. Among the more common types of exempt income are interest on municipal bonds, a portion of Social Security benefits, life insurance proceeds, gifts or inheritances, and the value of many employee benefits.

Gross income is reduced by adjustments and deductions. Among the more common adjustments are reductions for alimony paid and IRA and certain other retirement plan contributions. Adjusted gross income is used in calculations relating to various deductions, credits, phase outs, and penalties.

Business deductions.

Most business deductions are allowed regardless of the form in which the business is conducted. Therefore, an individual small business owner is allowed most of the same business deductions as a publicly traded corporation. A business is an activity conducted regularly to make a profit. Only a few business-related deductions are unique to a particular form of business-doing. The deduction of investment expenses by individuals, however, has several limitations, along with other itemized (personal) deductions.

The amount and timing of deductions for income tax purposes is determined under tax accounting rules, not financial accounting ones. Tax rules are based on principles similar in many ways to accounting rules, but there are significant differences. Federal deductions for most meals and entertainment costs are limited to 50% of the costs (with an exception for tax year 2021, 

The amount and timing of deductions for income tax purposes is determined under tax accounting rules, not financial accounting ones. Tax rules are based on principles similar in many ways to accounting rules, but there are significant differences. Federal deductions for most meals and entertainment costs are limited to 50% of the costs (with an exception for tax year 2021.

Bailment is a legal relationship in common law, where the owner transfers physical possession of personal property ("chattel") for a time, but retains ownership. The owner who surrenders custody to a property is called the "bailor" and the individual who accepts the property is called a "bailee". The bailee is the person who possesses the personal property in trust for the owner for a set time and for a precise reason and who delivers the property back to the owner when he or she has accomplished the purpose that was initially intended.

General.

Bailment is distinguished from a contract of sale or a gift of property, as it only involves the transfer of possession and not its ownership. To create a bailment, the bailee must both intend to possess, and actually physically possess, the bailable chattel. Although a bailment relationship is ordinarily created by contract, there are circumstances where lawful possession by the bailee creates a bailment relationship without an ordinary contract, such as an involuntary bailment. A bailment relationship between the bailor and bailee is generally less formal than a fiduciary relationship.

In addition, unlike a lease or rental, where ownership remains with the lessor but the lessee is allowed to use the property, the bailee is generally not entitled to the use of the property while it is in his possession. However, a lease of personal property is the same as a bailment for hire, where the bailee gains the right to use the property.

A common example of bailment is leaving one's car with a valet. Leaving a car in an unattended parking garage, however, is typically a lease or license of a parking space rather than a bailment, as the garage does not take possession of (i.e. exercise dominion or control over) the car. However, bailments arise in many other situations, including terminated leases of property, warehousing (including store-it-yourself), or in carriage of goods.

Governing law.

In the United States, bailments are frequently governed by statute. For example, the UCC regulates personal property leases. State bailment for hire statutes may also regulate the rights and duties of parties in the bailment relationship.

Bailment is a typical common law concept, although similar concepts exists in civil law.

Purposes.

There are three types of bailments, based on the purpose of the relationship:

1. for the benefit of the bailor and bailee

2. for the sole benefit of the bailor; and

3. for the sole benefit of the bailee.

Examples.

A bailment for the mutual benefit of the parties is created when there is an exchange of performances between the parties (e.g. a bailment for the repair of an item when the owner is paying to have the repair accomplished).

A bailor receives the sole benefit from a bailment when a bailee acts gratuitously (e.g. the owner leaves the precious item such as a car or a piece of jewelry in the safekeeping of a trusted friend while the owner is traveling abroad without any agreement to compensate the friend).

A bailment is created for the sole benefit of the bailee when a bailor acts gratuitously (e.g., the loan of a book to a patron, the bailee, from a library, the bailor).

A misdemeanor is any "lesser" criminal act in some common law legal systems. Misdemeanors are generally punished less severely than more serious felonies, but theoretically more so than administrative infractions (also known as minor, petty, or summary offences) and regulatory offences. Typically, misdemeanors are punished with monetary fines or community service.

Distinction between felonies and misdemeanors.

A misdemeanor is considered a crime of lesser seriousness, and a felony one of greater seriousness. The maximum punishment for a misdemeanor is less than that for a felony under the principle that the punishment should fit the crime. One standard for measurement is the degree to which a crime affects others or society. Measurements of the degree of seriousness of a crime have been developed.

In the United States, the federal government generally considers a crime punishable with incarceration for not more than one year, or lesser penalty, to be a misdemeanor. All other crimes are considered felonies. Many states also employ the same or a similar distinction.

The distinction between felonies and misdemeanors has been abolished by several common law jurisdictions, notably the UK and Australia. These jurisdictions have generally adopted some other classification (in the UK the substance of the original distinction remains, only slightly altered): in the Commonwealth nations of Australia, Canada, New Zealand, and the United Kingdom, the crimes are divided into summary offenses and indictable offenses. The Republic of Ireland, a former member of the Commonwealth, also uses these divisions.

In some jurisdictions, those who are convicted of a misdemeanor are known as misdemeanants (as contrasted with those convicted of a felony who are known as felons). Depending on the jurisdiction, examples of misdemeanors may include: petty theft, prostitution, public intoxication, simple assault, disorderly conduct, trespass, shoplifting, vandalism, reckless driving, indecent exposure, and possession of cannabis for personal use.

A summary offense or petty offense is a violation in some common law jurisdictions that can be proceeded against summarily, without the right to a jury trial and/or indictment (required for an indictable offence). In the law of the United States, petty offenses are typically those that carry the lightest maximum penalty.

United States.

In law of the United States, "there are certain minor or petty offenses that may be proceeded against summarily, and without a jury" These include criminal citations. Any offense that is punishable by the controlling law for more than six months of imprisonment must have some means for a jury trial. Some states, such as California, provide that all defendants are entitled to a jury trial (irrespective of the nature of their offenses). Some states provide that in all cases the defendant may demand a jury trial.

Under section 316 of the Immigration and Nationality Act (INA), a person convicted of a petty offense can be naturalized as a citizen of the United States.

Contempt of court is considered a prerogative of the court, as "the requirement of a jury does not apply to contempts committed in disobedience of any lawful writ, process, order, rule, decree, or command entered in any suit or action brought or prosecuted in the name of, or on behalf of, the United States" There have been criticisms over the practice. In particular, Supreme Court Justice Hugo Black wrote in a 1964 dissent, "It is high time, in my judgment, to wipe out root and branch the judge-invented and judge-maintained notion that judges can try criminal contempt cases without a jury."