Explainer

We have covered what federal knife law covers — manufacture, interstate commerce and importation — and why that leaves ownership and carry to the states.

This is the practical follow-on: how to find the rule that applies to you, without relying on a chart that may be years out of date.

Step one: the state statute

Every state publishes its current code online, and that text is authoritative in a way no summary is.

Search for your state name plus “code” or “revised statutes,” then look for the criminal offences title, and within it weapons offences. The terms that matter are usually “dangerous weapon,” “deadly weapon,” or a specific enumeration of knife types.

Read the definitions section as well as the offence. Statutes routinely turn on a defined term, and the definition frequently does not match ordinary usage — the same trap as the national parks rule, where the definition of “weapon” is narrower than people assume.

Step two: preemption

Preemption determines whether cities and counties may write their own knife rules.

In a state with knife preemption, the state statute is generally the whole answer. In a state without it, a knife that is lawful statewide can still be prohibited by a municipal ordinance, and you would have no way of knowing from the state code alone.

Search your state code for “preemption” alongside “knife” or “weapon.” If it exists, it is usually a short, clearly-worded section.

Step three: local ordinance, if needed

If your state lacks preemption, check the municipal code for the city and the county you are in. Most publish searchable codes online.

This is also where the answer changes as you drive, which is worth remembering on a trip that crosses several jurisdictions.

The separate questions

Five things are usually governed separately, and a single answer to “is this legal” often conflates them:

Ownership. Open carry. Concealed carry. Restricted places — schools, courthouses, government buildings, secure areas of airports. And rules for minors.

A knife can be lawful to own, lawful to carry openly, unlawful to conceal, and unlawful in a particular building, all at once.

And when it matters

If the answer has real consequences — you are moving, travelling with a collection, or facing an actual legal question — talk to a lawyer in that state.

This is general information about how to find the law, not legal advice about what it means for you.

This article was researched and drafted with the assistance of AI tools and reviewed, fact-checked and edited by Leonidas Clark before publication. It is general information, not legal advice.