If you are in a car accident where each driver was 50% at fault, what happens next depends upon the state in which the accident occurred. Below are the three major types of negligence law in effect in the various states. Which type of negligence law is in effect in that state affects your ability to sue or be sued for damages:
Pure contributory negligence: This is the most draconian type of negligence standard that only a few states have. It means if you were even 1% at fault for the crash, you cannot recover damages at all. The same holds for the other driver: If they were 1% at fault, they cannot recover damages. So, in a 50 50 accident, the injured driver theoretically cannot recover damages.
Pure comparative negligence: You can recoup damages in proportion to your degree of fault. If you are 50% at fault and have $5000 in damages, you could recover $2500.
Modified pure comparative negligence: This means you can also recover damages based upon your degree of fault, up to a certain percentage of fault. If you have $5000 of damages and were 50% at fault, you generally can recover $2500. But some states have a 49% threshold, so theoretically you could be barred from recovery.