When you play a bridge tournament, you play as part of a 4-person team. All the cards are dealt and placed in boards such that once they're played, they're replaced back as the North, South, East, or West hand.
Now your team of 4 is split into two partnerships, one playing all the N/S hands, one playing all the E/W hands. For any given hand of N,S,E,W, what counts isn't what your partnership does on your cards (either N/S or E/W), it's the delta between what your other partnership scored and what you scored. So, if you and X are playing North/South, and your other team members are playing E/W, then for every hand its your score - their score becomes your team score for that deck of cards.
In this way, there is no element of luck. Every team plays the same cards, every team plays both pairings (N/S and E/W), and only the difference matters. It's pure skill, both in bidding what you will make, and then playing the cards to actually make your bid. You can "win" the deck by causing someone who bid a grand-slam to lose a trick, and get the maximum points for that deck to your team.
Bridge is a truly excellent game. Simple rules, but incredibly challenging to execute correctly every time.