What is an eggshell plaintiff?
An eggshell plaintiff is an injured person who was more fragile than average, say from an old back injury or brittle bones. The rule says the person at fault pays for the full harm caused, even if a healthier person would have been hurt less. Utah's jury instruction says greater susceptibility does not reduce damages.
Last checked November 9, 2026 · Official sources (4)
How does the eggshell plaintiff rule work? An example
Example: two drivers are rear-ended at the same low speed. One walks away sore for a week. The other had a fused vertebra from an old surgery, and the jolt damages the level above it, leading to a second surgery. The at-fault driver cannot argue, "a normal neck would have been fine." If the crash caused the second surgery, that cost counts, even though it was bigger than anyone expected.
Why does the eggshell rule matter if you had a prior condition?
Adjusters often point to an old injury and say your pain is not from this crash. The rule answers part of that: a weaker starting point is not a defense. But you still have to show what changed. Records from before and after the crash, and a doctor willing to explain the difference, carry the claim.
There is a limit. You are not paid for the condition you already had, only for the worsening. One model instruction tells jurors to compensate any worsening of an existing condition that resulted from the defendant's negligence, not the condition itself.
Does Arizona use the eggshell plaintiff rule?
| State | Instruction given to jurors |
|---|---|
| Arizona | Award the full amount for all damages caused by the defendant's fault, even if the plaintiff was more susceptible to injury than a normally healthy person. |
| Utah | A more susceptible person is still entitled to the full damages legally caused by the defendant's fault. |
We did not find a Texas pattern instruction on a government site to cite here.
Eggshell plaintiff vs. pre-existing condition
A pre-existing condition is the fact: you had a bad knee before the fall. The eggshell plaintiff rule is how the law treats that fact: the at-fault side takes you as it found you and pays for the extra harm it caused, while you are not paid for the bad knee you already had.
Questions
Can an insurer deny my claim because of an old injury?
It may try, but greater susceptibility alone does not reduce damages the crash caused. The fight is usually over what part of your condition is new.
Do I have to tell the insurer about my prior injury?
Hiding it usually backfires, because old records surface. Being upfront lets your doctor explain what changed.
Find out if you are owed money.
A free case review. $0 upfront. No fee unless you win.
See if I’m owed moneySources (4)
- Utah Model Jury Instructions, Damages, checked 2026-11-09. “A person who may be more susceptible to injury than someone else is still entitled to recover the full amount of damages that were Legally Caused by [name of defendant]'s Fault.”
- Utah Model Jury Instructions, Damages, checked 2026-11-09. “An injured person who has a condition or disability before the time of an injury is not entitled to recover damages for that condition or disability.”
- Revised Arizona Jury Instructions (Civil), Personal Injury Damages (State Bar of Arizona), checked 2026-11-09. “even if [name of plaintiff] was more susceptible to injury than a normally healthy person would have been, and even if a normally healthy person would not have suffered similar injury.”
- Massachusetts Superior Court Model Civil Jury Instructions, Personal Injury Damages, checked 2026-11-09. “you may not award damages for that pre-existing condition itself. However, you should compensate PLF for any worsening of an existing condition that resulted from DFT's negligence.”