The good news is that, while Texas has laws against gambling not specifically authorized by the state, those laws tend to read somewhat Libertarian, take a look:
Sec. 47.02. GAMBLING.
(a) A person commits an offense if he:
(1) makes a bet on the partial or final result of a game or contest or on the performance of a participant in a game or contest;
(2) makes a bet on the result of any political nomination, appointment, or election or on the degree of success of any nominee, appointee, or candidate; or
(3) plays and bets for money or other thing of value at any game played with cards, dice, balls, or any other gambling device.
(b) It is a defense to prosecution under this section that:
(1) the actor engaged in gambling in a private place;
(2) no person received any economic benefit other than personal winnings; and
(3) except for the advantage of skill or luck, the risks of losing and the chances of winning were the same for all participants.

If you care to take a look at other laws, we originally cited these on our restrictions page:
While the penalties are pretty stiff for unlawful gambling, it says that the fact that the actor is doing the gambling in a private place is a defense and that the actor would receive nothing except his/her personal winnings. The third part of the law, even though the way it is written is kind of confusing, basically says that any kind of private game would be fine provided that there is nobody taking a vig out of the game.
Therefore, home games seem like they would be explicitly permitted by the law, as would online gambling, provided that you are conducting your gambling as a player and in a private place.
It comes as no surprise that almost all internet casinos offering their services in the United States also choose to allow players from Texas, and you may visit some of them below:
The good news is that, while Texas has laws against gambling not specifically authorized by the state, those laws tend to read somewhat Libertarian, take a look: Sec. 47.02. GAMBLING. (a) A person commits an offense if he: (1) makes a bet on the partial or final result of a game or contest or on the performance of a participant in a game or contest; (2) makes a bet on the result of any political nomination, appointment, or election or on the degree of success of any nominee, appointee, or...