Generally, a document is legal if its creator intends for it to be enforceable in a court of law. In order for a document to be legal, it must also adhere to the laws of the jurisdiction where it will be enforced. The document should also be properly signed, witnessed and filed to be considered legal.
When two parties voluntarily enter into an agreement and intend to make it binding and enforceable, the resulting contract is a legal document.
When a judge enters an order, it is a binding and legal document as there is recourse available if it is breached.
Petitions and Filings
When an individual or his attorney drafts, serves and files a petitions or motion with a court pursuant to federal, state and local laws, the documents produced are legal.
Wills and Trusts
When an individual signs and has witnessed a document that they intend to govern their assets, they have produced a legal document.
Laws, Proclamations and Acts
Laws, acts and congressional proclamations are all legal documents since they shape judicial actions and are enforceable.