Texas Penal Code section 49.01 defines intoxicated as not having the normal use of mental or physical faculties by reason of the introduction of alcohol, a controlled substance, a drug, a dangerous drug, a combination of two or more of those substances, or any other substance into the body. Or having an alcohol concentration of point zero eight or more in your blood.
The point at which you lose the normal use of your mental or physical faculties varies from person to person.
This doesn’t mean it’s absolutely illegal to have a beer while you’re carrying your handgun but if you become intoxicated you’re breaking the law
Texas 51% Sign
Under Texas law you cannot carry a firearm into a bar.
You’ll know it’s a bar because bars are required by the Texas Alcoholic Beverage Commission to post 51% signs indicating that the establishment derives more than 51% of its revenue through the sale of alcohol for on-site consumption.
A 51 sign will feature a 51% sign in large red numbers notifying you that carrying a handgun on the premises is a felony of the third degree.
This means that carrying into a 51% establishment could land you between 2 and 10 years in prison and up to a $10,000 fine.
What about the bar area of restaurants?
If it is a true restaurant, and they don’t derive 51% or more of their sales from the sale of alcohol for on-site consumption, you can carry anywhere inside of that restaurant–even the bar area. Basically, the whole building is either 51% or it isn’t.