system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The 11th amendment to the US constitution.
gpt
The 11th Amendment is fundamentally about the legal doctrine of sovereign immunity, which says that a sovereign state can't be held accountable in a court of law unless it consents to be, since it's the source of the law in the first place.

Originally, US states were effectively separate countries, so they had sovereign immunity.  After the US Constitution was ratified, the Supreme Court ruled that a particular clause in the Constitution (which said that citizens of one state could sue another state in the Supreme Court) had eliminated the sovereign immunity of the states in those suits.  The 11th Amendment was passed to reverse that and clarify that the states were still immune to suit in those cases.