In Red Dead Redemption 2, there are 90 challenges spread across 9 main categories required for 100% completion of the game. These challenges can only be completed one at a time, in a consecutive sequence. After you have completed all 90 challenges, you will unlock the legend of the east outfit.
Gambler 1
Win 5 Hands of Poker:
For this challenge, you don’t need to know how to play Poker. Reach the Poker table on Valentine’s and go all-in every time. Most of the time, your opponents will fold or lose.

Gambler 2
In Blackjack, Double Down and Win the Hand 5 Times:
You will need to reach the Blackjack table in Rhodes and double down every time you have a low number (16 or less).

Gambler 3
Win 3 Games of Five Finger Fillet:
The easiest table to play Five Finger Fillet is the one in valentine’s. For the challenge, by the way, you don’t need to win 3 games in a row. So first go to valentine, then strawberry, and finally Van Horn Trading post and beat the first opponent.

Gambler 4
Bust One Poker Opponent Out in Each Location:
To complete this challenge, you need to bust out an opponent in Flatneck Station, Saint-Denis, and Valentine. You don’t need to know how to play Poker. Reach the table and go all in every time.

Gambler 5
Win 3 Rounds of Dominoes Without Drawing Any Tiles Against 2 Or Fewer Opponents:
You have to reach the table in Saint-Denis, the easiest one for this challenge. All you have to do is win three rounds, not a game. Your goal is to put all your tiles down without taking one from the stock. You don’t need to win 3 rounds in a row. Ignore points and other rules; simply place your tiles, always making sure to have room for a couple of moves later.

Gambler 6
Beat the Blackjack Dealer in Every Location:
You need to beat the Blackjack dealer in Rhodes and Van Horn Trading post to complete the challenge.

Gambler 7
Beat the Five Finger Fillet Player in Every Location:
You have to go to Valentine, Strawberry, and Van Horn Trading posts and beat the first opponent.

Gambler 8
Win 3 Hands of Blackjack With 3 Hits Or More:
Reach the Blackjack table in Rhodes, and ask for a card every time your total is under 18. The goal is to hit three times. So, in the end, you should have at least five cards – and win against the dealer. There are no tricks for this challenge; you just need to have a lot of patience. Keep betting two cents every time and wait for lower hands.

Gambler 9
Win 3 Games of Dominoes In A Row:
You have to reach the table at Emerald Station, the easiest one for this challenge, and make sure to have only one opponent. What you have to do is win three games in a row, not just rounds. It means you can lose a round or two as long as you are winning the game. Here the round is won by the player who first puts down all his tiles. The first who puts down all tiles and calls “Domino”, gets points based on the number of pips in the losing player’s hand. The first player who reaches a total of 60 points or more wins the game. The trick is easy.
Always play first the tiles with the highest number of pips, and make sure to have options available for your next moves. If you collect too many tiles from the stock and your opponent is just two tiles away from winning, you are about to lose. To avoid resetting your winning streak, leave the table and rejoin for a new game. Do not save and reload. Otherwise, the game will reset your winning streak.

Gambler 10
Win 3 Hands of Poker in A Row:
For this challenge, you don’t need to know how to play Poker. Reach the Poker table on Valentine, and go all-in every time. Most of the time, your opponents will fold or lose. The goal is to win three hands in a row. If the pot is split, don’t worry, that’s considered a winning hand.
