Contingency fee
A fee paid only if the lawyer obtains a recovery, calculated as a percentage of it.
A contingency fee is a fee arrangement in which the lawyer is paid a percentage of the client's recovery and only if there is a recovery. It is common in personal-injury work, which lets injured clients pursue claims without paying hourly fees up front.
Contingency arrangements must be in writing under Model Rule 1.5(c), state the method of calculation, and are prohibited in certain matters (e.g., most domestic-relations and criminal cases).