The default effect, a concept within the study of nudge theory, explains the tendency for an agent to generally accept the default option in a strategic interaction. The default option is the course of action that the agent, or chooser, will obtain if he or she does not specify a particular course of action.

A default, in computer science, refers to the preexisting value of a user-configurable setting that is assigned to a software application, computer program or device. Such settings are also called presets or factory presets, especially for electronic devices.

In finance, default is failure to meet the legal obligations (or conditions) of a loan, for example when a home buyer fails to make a mortgage payment, or when a corporation or government fails to pay a bond which has reached maturity. A national or sovereign default is the failure or refusal of a government to repay its national debt.

n. See also: default judgment

n. if a defendant in a lawsuit fails to respond to a complaint in the time set by law (commonly 20 or 30 days), then the plaintiff (suer) can request that the default (failure) be entered into the court record by the clerk, which gives the plaintiff the right to get a default judgment. If the complaint was for a specific amount of money owed on a note, other money due, or a specific contract price (or if the amount due is easy to calculate) then the clerk of the court can enter a default judgment. If proof of damages or other relief is necessary, a hearing will be held in which the judge determines terms of the default judgment. In either case the defendant cannot speak for himself/herself. A defendant who fails to file an answer or other legal response when it is due can request that the default be set aside, but must show a legitimate excuse and a good defense to the lawsuit. See also: complaint default summons

Default judgment is a binding judgment in favor of either party based on some failure to take action by the other party. Most often, it is a judgment in favor of a plaintiff when the defendant has not responded to a summons or has failed to appear before a court of law.

In finance, a default option, credit default swaption or credit default option is an option to buy protection (payer option) or sell protection (receiver option) as a credit default swap on a specific reference credit with a specific maturity. The option is usually European, exercisable only at one date in the future at a specific strike price defined as a coupon on the credit default swap.

In law, a default is the failure to do something required by law or to comply with a contractual obligation. Legal obligations can arise when a response or appearance is required in legal proceedings, after taking out a loan, or as agreed in a contract; failure to carry them out puts one in defaults of the obligations.