MBE Rules · Criminal Law

Causation — actual and proximate

The rule

Actual cause: but-for the defendant's conduct, the harm would not have occurred. Proximate cause: harm is the natural and probable consequence; intervening acts break the chain only if unforeseeable. Eggshell-skull and victim's pre-existing condition do not break the chain.

In plain English

To be responsible for a crime, the defendant's actions must directly lead to the harm, and the harm must be a foreseeable result of those actions.

Worked example

The defendant sets a fire, and smoke causes a nearby driver to crash. The crash is a foreseeable result of the fire, so the defendant is responsible for the harm.

Memory hook

CAUSE: But-for + natural flow. Actual cause needs direct link; proximate cause needs foreseeability.

The trap

Students think: any intervening act breaks causation. Wrong, because only unforeseeable acts break it. The actual test is foreseeability.

How examiners test it

MBE setup: defendant's act + victim's pre-existing condition or minor intervening act. Trap: assuming chain breaks. Answer: chain stays unless act is unforeseeable.

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