MBE Rules · Torts
Products liability — manufacturing defect
Rest. 3d Torts: Prod. Liab. §2(a)
The rule
A product contains a manufacturing defect when it departs from its intended design even though all possible care was exercised in its preparation and marketing. A commercial seller in the chain of distribution is strictly liable for physical harm caused by such a defect, regardless of fault.
In plain English
This is the classic 'one-off lemon' theory — the individual unit differs from the manufacturer's own specifications. Plaintiff need not identify how it went wrong, only that this unit deviated from the design. No proof of negligence in manufacture is required.
Memory hook
Design defect = the blueprint is bad. Manufacturing defect = the blueprint is fine, but THIS unit is bad.
The trap
Students conflate this with design defect and apply risk-utility. Manufacturing defect uses a pure deviation-from-specification standard — no reasonable-alternative analysis needed.
How examiners test it
Isolated malfunction: a bottle explodes, a single tire blows, a lone contaminated food item. Compare against the manufacturer's other same-model units.
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