Most personal injury case retainer agreements provide for a one-third legal fee contingent upon a recovery (by verdict or settlement) and will include language something like this:

The percentage fee is calculated on the net sum recovered after deduction for expenses and disbursements properly chargeable to the case such as investigation and expert fees.

So

A contingency fee is a fee that is not earned or paid until and unless a certain event occurs – in injury cases this means there has to be a monetary recovery for the injured person’s damages.

The legislatures and courts in most states have become very involved in regulating and overseeing contingency fee relationships