SAN ANTONIO -- It's well known that gambling is illegal in Texas.

But with Tuesday night's search for a well-known poker player's home -- as part of a sports gambling investigation --many people want to know where the state draws the line.

Poker is more popular than ever. Whether it's Texas Hold 'Em, Draw or Stud.

How do you know if your game is legal in the Lone Star State, though?

The district attorney's office said, in general, a friendly poker game is legal only under certain conditions.

"If it's done in a private place where everybody has the same chance of winning, odds of winning are equal for everybody and the house is not getting a cut of the action, that's fine," said one district attorney official.

A bet at Retama is OK. So is betting on the dog races. And you can buy as many lottery tickets as you want.

"As a general rule, the lawful types of gambling that are commercial gambling are charitable bingo, the Texas lottery, horse racing, dog racing, and charitable raffles," said a district attorney official.

But watch out for those eight-liners. There are strict rules about their use.

There must be limited non-cash merchandise prizes and cannot be operated for a profit.

"If an eight-liner is involved, a bet of more than $5, or 10 times the amount bet on a single play of the game (is) being operated illegally," said a district attorney official.

What about your office football pool? It's legal when everyone has an equal chance of winning, it's not operated in a public place, and the house isn't getting a cut of the action.