lub po prostu wynagrodzenie prowizyjne
a czasem nazywa się to 'wynagrodzenie za sukces'

Definicje dwóch rodzajów wynagrodzeń:
The difference between representation on a "time and material" basis and a "retainer and contingency" basis lies in the treatment of attorney's fees. On a "time and material" basis, attorney's fees are charged on an hourly basis regardless of the outcome of the case. That is, whether the client pays some or all of the attorney's fees does not depend on whether the client wins or loses the case. The attorney does not risk on the outcome of the case.
On a "retainer and contingency" basis, the attorney risks on the outcome of the case. ... After the retainer is paid, the client pays no further attorney's fees unless and until the client receives a favorable outcome in the case. At that time, the attorney shares or takes a contingency percentage of the favorable outcome.