Short term: plenty of luck
Long term: almost 0 luck.
So you may run horrible in cash games for a while, but you will also have times when you will run super hot. There will be times where it seems every time you hit 2 pair somebody rivers a higher 2 pair or hits a set, and everytime you hit a set it is an under set or somebody hits a flush draw, but there will also be times when you are on the good end of every cooler. There will be times when you will lose almost every hand where you get your money in as a favourite and there will be times where it seems that you simply cannot lose a pot. There will also be times where it seems that the villain hits the top of his/her range every time, and likewise there will be times when it seems they constantly hit the bottom of their range.
But over a long period of time, when you get your money in at a 2:1 favourite, you will win that pot 2 out of 3 times. And in the long term, when you get the money in when you dominate your opponent's range, you will come out on top.
Tournaments are a different boat. You have to get REALLY lucky to go deep in an MTT...ie. you must get good cards, your hands must hold up etc. Over the 5 or so hrs it might take to place high in an MTT, you'll be all in playing for stacks (or close enough to it that you probably won't recover) several times. Even if you have AA vs KK 5 times in an MTT, unless you get a little lucky you could very well be out. You also will be forced to take stupid flips at times, because that is just how tournaments work.
But the same applies...over long term there is little luck in MTTs. Eventually you'll get that magic tournament...i just think that long term for MTTs is quite a big higher than for cash games, because luck is fairly inherent when blinds are so crucial. You could play 10k hands and call it fairly long term for cash games (tho sure you could run bad over the entire stretch) but you couldn't call 100 MTTs long term.