"Nobody gets hurt" is an agreement that groups can adopt as part of their social contract, in which all players understand each other's lines (personal boundaries) and intend not to cross them. A game played under an understanding that nobody gets hurt is one that will not include content that is potentially harmful or emotionally distressing. The concept was first described by Meguey Baker.
"Nobody gets hurt" is contrasted with "I will not abandon you", in which boundaries are expected to be pushed but all players agree to remain engaged and support each other through the challenging content.
"Nobody gets hurt" and "I will not abandon you" preceded the widespread creation and adoption of safety tools in role-playing games. Avery Alder has said that, although the notions of "Nobody gets hurt" and "I will not abandon you" were important when first created, "such positions are inherently reflected and communicated through the variety of safety mechanics and practices available today" without needing to be stated in full.
Although "nobody gets hurt" is intended to ensure that players stay within their comfort zones during gameplay, its use requires an up-front discussion of boundaries as part of session zero before gameplay can begin, which can be potentially distressing for some players. (There is no safety tool that will eliminate harm for all players, and the problem of up-front discussions still exists when using safety tools such as lines and veils or a consent checklist.)