The practice of law is defined by statutes and case law.
Section 81.101 of the Texas Government Code states:
(a) In this chapter the "practice of law" means the preparation of a pleading or other document incident to an action or special proceeding or the management of the action or proceeding on behalf of a client before a judge in court as well as a service rendered out of court, including the giving of advice or the rendering of any service requiring the use of legal skill or knowledge, such as preparing a will, contract, or other instrument, the legal effect of which under the facts and conclusions involved must be carefully determined.
(b) The definition in this section is not exclusive and does not deprive the judicial branch of the power and authority under both this chapter and the adjudicated cases to determine whether other services and acts not enumerated may constitute the practice of law.
(c) In this chapter, the "practice of law" does not include the design, creation, publication, distribution, display, or sale, including publication, distribution, display, or sale by means of an Internet web site, of written materials, books, forms, computer software, or similar products if the products clearly and conspicuously state that the products are not a substitute for the advice of an attorney. This subsection does not authorize the use of the products or similar media in violation of Chapter 83 and does not affect the applicability or enforceability of that chapter.
The above statute does not provide an exhaustive list of what constitutes the practice of law. The Texas Supreme Court has held that the courts ultimately decide what is the practice of law.
Section 81.102 of the Texas Government Code states who may practice law in Texas:
(a) Except as provided by Subsection (b), a person may not practice law in this state unless the person is a member of the state bar.
(b) The supreme court may promulgate rules prescribing the procedure for limited practice of law by:
(1) attorneys licensed in another jurisdiction;
(2) bona fide law students; and
(3) unlicensed graduate students who are attending or have attended a law school approved by the supreme court.
Other statutes also regulate the practice of law.
Section 83.001(a) of the Texas Government Code prohibits a "person, other than a person described in Subsection (b), may not charge or receive, either directly or indirectly, any compensation for all or any part of the preparation of a legal instrument affecting title to real property, including a deed, deed of trust, mortgage, and transfer or release of lien. Subsection (b) exempts licensed attorneys, real estate brokers or salesmen and mineral property lease transactions.
Section 38.122 of the Texas Penal Code prohibits a person from holding himself out to be a lawyer unless licensed to practice law if it is done with an intent to obtain an economic benefit.
Section 38.123 of the Texas Penal Code prohibits a person from taking certain actions with respect to personal injury claims if done with an intent to obtain an economic benefit.