MBE Rules · Torts
Alternative Liability
Summers v. Tice
The rule
When two negligent defendants create identical risks and the plaintiff cannot prove which caused the harm, the burden shifts to each defendant to disprove causation.
In plain English
Alternative liability applies when two or more defendants are negligent and create the same risk of harm, but the plaintiff cannot determine which defendant caused the injury. In such cases, the burden of proof shifts to the defendants to show that they did not cause the harm.
Worked example
Two manufacturers produce similar defective products that cause a fire in a store. The store owner cannot determine which manufacturer's product was responsible for the fire. Under alternative liability, both manufacturers must prove that their product did not cause the damage.
Memory hook
When two wrongs create a risk, the burden flips to prove who didn't cause the harm.
The trap
Exams may present scenarios where students must distinguish between alternative liability and joint liability, leading to confusion about the burden of proof.
How examiners test it
Questions often involve fact patterns with multiple defendants and a shared risk, testing the student's understanding of how the burden of proof shifts under alternative liability.
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