Poker is a game.
Any "game" has some portion of luck, otherwise it would not be a game, but a task.
Look at the difference in how a person plays a cash game versus a tournament.
While cash games will eventually become a zero sum game, tournaments will allways be a game of success versus failure.( meaning the more correct you play in a tournament, the more skill than luck one will need to win. [ luck is always some part of the game, and may factor as little as 3% of the time, and is still needed to win regardless] )