When can a defendant not implead a third-party defendant?

A defendant cannot implead a third-party defendant when the defendant denies liability entirely because impleader is a procedural mechanism that allows a defendant to bring another party into the lawsuit, but it typically only applies when the original defendant believes that the third-party is liable for all or part of the plaintiff’s claim against them. By denying liability entirely, the defendant suggests that they have no obligation to the plaintiff, and therefore, they cannot assert that another party is responsible for any damages, making impleader inappropriate in this scenario.

In this context, options addressing recovery from the third party, insufficient evidence presented by the plaintiff, or the defendant already paying damages do not inherently prevent impleader. The critical element is the defendant's acknowledgment of potential liability, which is absent when they deny it completely.