DataX, you pretty much got it.
I’ll try to avoid another wall of text, but here goes:
Setting:
(Disclaimer: I’m not a dice setter nor have I ever met one I didn’t think was a crackpot so I know only the very basics)
The object of dice setting is to throw the dice so that they spin only around a single axis. So rather than spinning around all three axes and landing randomly the dice only tumble end-over-end in the air, when landing on the table, and when hitting the back wall. Doing this eliminates the numbers on each die that the axis runs through.
Quick fact: The numbers opposite each other on a die always add up to 7. So 1 is opposite of 6, 2 is opposite of 5, and 3 is opposite of 4.
As you can see from this picture the dice are set so that the 1’s and 6’s are on the inside & outside of the dice. If those dice are thrown so that they only ever pivot around the invisible line that runs through the 1 & 6 sides, the 1 & 6 will not come up. This changes the chance of rolling a 7 from 1-in-6 to 1-in-4 and completely remove the 2, 3, and 12 craps numbers, significantly increasing your edge on the come-out roll on the pass line. Other forms of setting can LOWER the chance of rolling a 7, giving pass line bettors the edge after the come-out roll.
Casinos do require you to hit the back wall so dice setters aim to land on the felt just about an inch away from the wall so they just lightly touch the wall and stay on-axis. They will generally do this only from the straight-out position at the end of the table. In order to stay on-axis the dice should be roughly less a centimeter apart throughout the whole toss.
If it seems unlikely someone can precision-toss dice to within an inch of the back wall about 10-12 feet away while keeping the dice tumbling only end-over-end and within a centimeter of each other…that’s because it is. There are most likely only a handful of people in the world who can do it consistently enough to gain an edge over the casino. Even if they can, keep in mind they must be the shooter in order to have the edge so they need a dead table or one with very few other people on it.
So long as the dice hit the back wall dice setting is NOT considered cheating.
Mike Shackleford at the Wizard of Odds (great site) had a 500 roll challenge with two skilled shooters and the results were inconclusive. Keep in mind this was in a controlled environment:
The Wizard of Odds - Dice Setting
Sliding:
Sliding, unlike setting, is definitely a cheat move. The idea is to slide a die down the felt so it doesn’t roll at all and the top face remains the top face. As it’s a cheat move, attempting to slide both dice down the table is very obvious and just won’t work. Dice sliders will instead toss one die at or above eye level, distracting the dealers and box, while sliding the other.
It’s an extremely difficult move to pull off but also extremely profitable. These players will generally play single-roll proposition bets. Imagine if you knew one of the dice would be a 6. Just place a bet on the 12 and you have a 1-in-6 chance of a 32-to-1 payout. That is a massive, massive edge over the house.
Even the best dice slide technique is pretty obvious when overused. Generally one or more of the staff are colluding with the sliders. With a play that obvious either the staff is in on it or stupid and either way they’ll be fired if they let it happen. A couple of dice sliders were caught at the Wynn after having won nearly $150,000 in a very short amount of time. Here’s a link to the article. The article doesn’t mention it but everyone from the craps crew to (I believe) the shift boss were fired for not catching it before they’d cashed-out and left.
