Gamers all know that sprawling, vast open-world games would be nothing but empty sandboxes without anything to fill it. Thus, developers add in side-missions, Easter Eggs and mini-games to give players fun side objectives to enjoy instead of pursuing the main storyline, something all gamers are guilty of.

Related: Minigames That Are More Fun Than Their Base Games

One common mini-game present in open-world games are ones based on cards, either borrowing card games from real-life or making up their own entirely. They are often the most convoluted games to learn with pages upon pages of rules, but those that do take the time to learn and master it will find hours of bonus content they can enjoy.

7 Poker - Watch Dogs

Four players gathered around a poker table with cards and chips, ready to play.

This action-packed sandbox title follows the story of vigilante hacker Aidan Pearce as he pursues a revenge quest after his niece was murdered in a fictional version of Chicago in 2013. Players were given the freedom to explore the map as they see fit, and pursue other activities other than the main quest, such as side-missions, accosting the locals, driving vehicles, and of course, hacking almost everything in sight.

Not only that, but players can also try their hand at games of chance and bluffing--namely poker. It is one of the seven mini-games on offer, and perhaps one of the most fun. There are four different levels of poker players can choose from, ranging from low stakes, to medium stakes, high stakes and super stakes. Of course the higher the stakes, the higher the cost to play but also the reward. And for players who may be inexperienced, they can always rely on Aidan's skills as a hacker to cheat.

6 MesuKing - Yakuza Kiwami

Title cars for MesuKing, a supposed game of battle bug beauties.

Yakuza Kiwami brought the classic Yakuza title to more modernized hardware, improving upon gameplay components and graphics fidelity. Players take on the role of Yakuza member Kiryu as he takes the fall for the murder of a mob boss to protect his best friend Nishikiyama and childhood friend Yumi. Other unfortunate incidents within the mob syndicate raise tensions, causing a civil war to disrupt that turns the structure of the entire family on its head.

Related: Yakuza Best Minigames in the Series

What better way to relax and take time away from the hectic life of a Yakuza member than with a fun card mini-game? In Kiwami, players can experience MesuKing, a game in which players will have a hand of insect cards and ability cards they can bolt onto their insects. They will then play rock, paper, scissors, and the winner will then get to apply skill cards against their opponents' insect, and the game will continue in this fashion until one loses all of their health.

5 Three Card Poker - Grand Theft Auto 5

The player trying their hand at poker in Grand Theft Auto V.

Three unlikely allies team up together to pull off the most dangerous heist of their lives in a city that could eat them alive, filled with people they cannot trust, including one another. They must also contend with the dangers of the criminal underground and the US government, and not to mention the difficulties players will bring on themselves when they break laws and bring down the police on their head with they inevitably commit the titular crime.

Unsurprising, Grand Theft Auto V allows players to opportunity to gamble away their virtual money in casinos, which includes a unique poker game. The player will be put up against the card dealer, and they will play from a single deck. The rules are the opposite to Texas Hold'Em, which players should bear in mind when playing. Due to its unique rules, three card poker stands out as one of the most fun mini-games in GTAV, and open-world games as a whole.

4 Caravan - Fallout: New Vegas

A game of Caravan in progress, which uses ordinary playing cards.

Obsidian's take on the Fallout franchise was wildly successful, earning praise and acclaim from critics and players alike. New Vegas took the players to the Mojave Desert, where they assumed the role of a courier that found themselves shot in the head at the start of the game after delivering a platinum chip to one of the players in the struggle for power in New Vegas. Along with exploring the various landmarks of the desert, delving into the vaults scattered throughout the sand and meeting the colorful inhabitants, players can also indulge in some gambling.

One such game is caravan, the staple card game for the residents of fictionized Mojave. Two opposing players will build three stacks (caravans), with the goal to be for the cards to add up to a number that is between a specific set of numbers (21 being too low and 26 too high), making it rather similar to a game of blackjack, with more rules to make the game slightly more difficult. While it may take a few rounds to memorize all the rules, once a player does, they will be hooked.

3 Blackjack - Red Dead Redemption 2

First person perspective of a red poker table, with several cards and hands visible.

In a fictionalized United States set in 1899 during the twilight years of the cowboy era, main character Arthur Morgan and his posse the Van der Linde gang find themselves at odds with the wealthy oil tycoon Leviticus Cornwall who then hired the Pinkertons to hunt them down. When not on quests that further the plot line, players are free to roam as they please, taking in the beautiful landscapes on horseback and partaking in whatever else Red Dead Redemption 2 has to offer.

Related: The Weirdest Things You Can Actually Do In Red Dead Redemption 2

One such thing is blackjack which can be played in four various locations across the world map. In the game, the rules are the same, with players aiming to build a hand that is as close to 21 as possible. Players will take turns to either take another card or stay with the hand they have. Once all players stand down, they reveal the cards, and the one closest to 21 wins. Of course, in Red Dead 2 the stakes are higher, as there is money on the line.

2 Triple Triad - Final Fantasy 8

A card game in progress with cards lining the side, the name of the game in the center.

The eight installment in the long-lasting Final Fantasy series brought players a new squad of characters including Squall and Rinao, bringing the story of warring nations, with the party of antagonists finding themselves caught in the middle. In typical FF fashion, the world map is split across several different locations each with their own unique terrain, and the standard turn-based combat fans have come to expect. What they might not have expected however, is a card game.

Triple Triad is available to play through a side-quest, and supposedly the game was created by a fortune-teller, who used a deck of modified tarot cards to play. It spread to soldiers before becoming a game popular to all. It is played on a three-by-three grid, and the deck consists of three different types of cards. Players will then put one card on one of the available spaces on the board, and in order to win, the majority of played cards must be in the players color. Though one of the more involved card games, it is also one of the most fun to play.

1 Gwent - The Witcher 3: Wild Hunt

An on-hoinh game of gwent in the Witcher, the board almost full of cards.

The Witcher 3 proved itself as one of the greatest open-world games, putting players in the boots of Geralt of Rivia, the main protagonist of the games and the series of books it is based on, as he travels through a fictional medieval-fantasy world, battling with the horrors of the world as he tracks down his adoptive daughter as he flees the relentless pursuit of the titular Wild Hunt. The world is popularized with places of note, NPCs, side-quests, bounty boards, and the game everyone loves: Gwent, a mini-game that proved so popular it became a video game in its own right.

Two players will have a board of three tiers, some of which are specific to a category of cards, Players will build an army consisting of combat, abilities, and effect cards, each of which can bolster their army, or have an adverse effect on the opponents' army (such as weather cards). To win, the totaled number of the cards combined must be higher than the opponents.

More: Best Strategy Card Games Of All Time