From TPW website:
Important notice: Crossbows are lawful for any person during the Archery-Only Open Season in all counties except Collin, Dallas, Grayson and Rockwall counties, where no person may use a crossbow to hunt deer during the Archery-Only Open Season (Oct. 1 - Nov. 4, 2016) unless the person has an upper-limb disability and has in immediate possession a physician's statement that certifies the extent of the disability. An upper-limb disability is a permanent loss of the use of fingers, hand, or arm in a manner that renders the person incapable of using a longbow, compound bow, or recurved bow.
Any person, regardless of physical ability, may use a crossbow to hunt game animals or game birds in any county, including Collin, Dallas, Grayson and Rockwall counties, during a general open season or Eastern spring turkey season.
An archery endorsement is required to hunt deer during the Archery-Only Open Season. An archery endorsement is required to hunt deer at any time in Collin, Dallas, Grayson and Rockwall counties, including during the general open season (Nov. 5, 2016 - Jan.1, 2017).
A crossbow is lawful for game animals and game birds, provided:
the crossbow has a minimum pull of 125 pounds;
the crossbow has a mechanical safety; and
the crossbow stock is not less than 25 inches in length.
Telescopic sights are lawful.
God bless John Wayne!