One advantage that video poker has over regular slot machines is that you can determine the return of the game by reading the pay table on the front of the machine. Most video poker games use the combinations of hands that can be made from a standard 52 card deck. I say most because there are some Joker Poker Games that use one or two Jokers added to the 52 card deck. One popular variation of the game is Deuces Wild which uses a 52 card deck but the deuces are wild cards. With a set number of combinations that can be made from the cards used in the game, the payout can be calculated by how much the machine pays for each winning combination.
Video poker is a very volatile game, about four times as much as blackjack. In any form of gambling, short-term results mostly depend on normal mathematical randomness (what some might call luck). However, in the long run, results mostly depend on skill. If you play a game with a return of 100.76% perfectly, that does not mean that you will have a 0.76% profit every time you play. The 100.76% is an EXPECTED return. Much in the same way, if you flip a coin ten million times, the expected number of tails will be five million, but it is unlikely you will hit five million on the nose. Actual results will vary significantly from expectations, but the more you play, the closer your actual return percentage will get to the expected return.