If you know how to count cards in a single-deck blackjack system, you will always come out ahead. If you have a computer to calculate the probabilities for you, you can consistently come out ahead in 5-deck casino blackjack games, too, just with a larger variance. That is probability.
Luck is the opposite. Dice is pure luck: no matter what you do, the probabilities do not change and you have no control over how much you win or lose.
Poker is mostly luck: a properly run poker game is nothing but pure luck deciding the outcome of the game, and the players maneuvering for advantage around it.
There is very little randomness in starcraft - your opponent's decisions and actions are not randomness, but an outcome of their experience and skill, similar to how your own actions are not random, but an outcome of your own experience and skill. The randomness factor mostly comes in at a very few points, such as exactly which mineral field each player starts at, and is almost never the deciding factor.
Edited 1 time(s). Last edit at 06/27/2012 10:44AM by vortexmagus.