Craps Superstitions
Same Dice

If a die goes off the table in craps, players consider it very bad luck to use the same die again. If the shooter wants to use the same dice, he must shout “same dice” immediately. If not, players believe the die or dice will be tainted and produce losing rolls.
No Seven

Some players believe that just saying the word “seven” is enough to invoke a seven, causing all bets on the table to lose. Some players say “big red,” when they want to make reference to a seven without actually saying the word.
One Hand

Players consider it bad luck to pass the dice from hand to hand before rolling. In some cases, the casino may also prohibit it, as it may increase the chances of someone slipping loaded dice into the game.

Roulette Superstitions
Trends

The biggest superstition in roulette is that there is some meaning to a trend in roulette, for example five reds in a row or six numbers in the first dozen in a row.

The reality is that unless the wheel is somehow biased, which is unlikely in a modern live casino and impossible if you play roulette in an online casino, past results have no bearing on future results.

Five reds in a row make the next spin coming up red no more or less likely than five blacks in a row.
Lucky Numbers

Many players have particular lucky numbers that they like to play in roulette. People should by all means play their lucky numbers since this adds to the fun of the game. The reality of course is that no number is more or less likely to come up for one person than for anyone else.