45 U.S.C. § 55 — Contract, rule, regulation, or device exempting from liability; set-off

This section stops railroads from trying to write their way out of liability, but lets them subtract certain payments already made. First, any contract, rule, regulation, or device whose purpose is to let a common carrier escape liability created by this chapter is void, it has no legal effect, to that extent. Second, there's an exception in the carrier's favor: in a lawsuit brought against a common carrier under this chapter, the carrier may set off (subtract from any damages owed) any amount it already contributed or paid, through insurance, a relief benefit, or an indemnity, to the injured employee, or to whoever else was entitled to it, on account of the same injury or death that the lawsuit is about.