For almost 50 years, Uno has been the go-to card game of choice for families and friends around the world. Whether you’re on a break, at the beach, trying to pass the time in a power outage, or playing under a blanket tent on a sleepover, Uno is the card game that literally everyone knows how to play. You can play with your grandma or your 5-year-old sibling, and everyone in between.

Invented in 1971 by Merle Robbins, a barber from just outside of Cincinnati, Ohio, Uno has gone on to sell hundreds of millions of decks and become one of the most beloved games of all time. Uno is played in over 80 countries around the world, and in 2017, became the number one most popular game in America, passing Monopoly, Life, and every other game in its path. The following year, Uno was inducted into the National Toy Hall of Fame, alongside Pinball and the Magic 8-Ball.

The genius of Uno is rooted in its simplicity. Four people from four opposite ends of the globe, who speak four different languages and operate in four completely different cultures, could most likely sit down around a table and play Uno together with ease. There is something beautiful about that, and it’s one of the main reasons The Hundreds wanted to work with Uno. The game brings all kinds of people together and breaks down barriers.

The concept of Uno also flies in the face of everything we grew up learning about games. On the back of the box of our The Hundreds X Uno cards, Bobby Hundreds drops a gem that sums it up perfectly, saying, “Most games in life are about how much you have. This one, however, is about losing it all. It’s not a race to the bottom, it’s about getting back to what’s most important. He who dies with the most toys loses!”

Sure, Uno is a game the whole family loves and it puts smiles on everyone’s faces blah blah blah, but real Uno players know it’s not all about laughing and hugging each other and cutting the last slice of pizza in half. No, Uno can be contentious, and it can get intense. In fact, the game of Uno was created in the first place because of an argument good old Merle had with a friend at his barbershop about the rules of Crazy Eights. So, Merle said forget this game, I’m making my own. I think we’ve all played with a Merle before.

But that kind of attitude is exactly what has kept Uno hot in the streets for a half-century. While every other game fizzles out as people get bored of it, Uno is constantly reinvented by its players. Every single household has a deck of Uno cards, and each and every one of those households play Uno by a different set of rules. House Rules are what sets Uno apart, allowing you to ratchet up the heat on an already spicy game by removing any and all morsels of mercy built into the official rulebook.

Over the years, the main purpose of Uno’s social media accounts has been to foster this creativity, championing great ideas for house rules while simultaneously squashing the outlandish ones. But at the end of the day, you can play however you want. And then, you pass your way of playing Uno down to the next generation, and so on and so forth. This has been going on since the beginning with Uno, and now, nearly 50 years later, here we are, fighting on Twitter.

I scoured the internet to find all the most common Uno House Rules, as well as some truly insane ones that are sure to pop that last in-tact blood vessel in your Uncle’s forehead this holiday season.

But first, I asked the rest of the team how they grew up playing.

Sandy in Digital Marketing: “You can bounce Draw 2 cards, meaning if someone puts a Draw 2, you can keep the Draw 2 cards going and hope you’re not the one without one. SO MUCH MORE FUN AND EVIL. However, this rule does not apply with Draw 4 cards because we’re not that evil.”

Allison in Photo: “All I remember is that you were allowed to stack Draw 2 and Draw 4 cards on top of each other as much as you wanted.”

Awad in Customer Service: “All cards can be bounced (similar to Sandy) but also includes Draw 4s and a modified game that plays with 3 cards at the start to do speed rounds.”

David in Graphics: “Everything gets stacked. Draw 4s, Draw 2s, Skips, Wilds, Reverse cards. If you have nothing to play, you keep drawing until you pull a card you can play. No mercy. A lot of upset siblings growing up.”

Pretty standard stuff from The Hundreds team. As you can tell, the Draw Stacking debate got a little heated in the office. But nobody had any super weird modifications to the game, at least not like some of the other ones I found online. Here are all the different Uno House Rules you can find on the internet, in no particular order because we’re already starting some fights with this and I don’t want to make it any worse.

1. Stacking Draw 2 and Draw 4, one of the most hotly contested House Rules in the game.
2. Use Skip and Reverse as a defense against Draw cards. Basically, if you get hit with a Draw 2 or Draw 4, you can drop a Reverse to turn the Draw card back on the person who put it down or use a Skip to send the Draw card to the shmuck sitting after you in the rotation.
3. Can play two identical number cards at once. If someone puts down a Yellow 5, you can drop a Red 5, Blue 5, and Green 5 if you have them.
4. You can add number cards of the same color together to play on the top card. For example, a Green 8 is on top of the pile. The next player can play a Green 6, Green 2, and Green 0 together to equal the 8. The 0 cards are always free plays with other number cards of the same color in this scenario.
5. You can play a matching card to the card on top of the pile, no matter whose turn it is. If a Blue 2 is on top, and you also have a Blue 2, drop it fast. The player whose turn it should have been must draw a card before they go as a penalty for not being quick enough.
6. Dropping any color 0 card gives the player Peek Pick Pass capabilities. They can look at anyone’s hand, and optionally give them a card or take a card, though it can’t be played to give away your last card.
7. Wild cards change places. Dropping a Wild means you physically get up and switch places with another player in the rotation.
8. The person to the left of the dealer goes first. And if you really want to get technical, the rules state that each player draws a card and the player with the highest number is the dealer.
9. Everyone knows that if you can’t play a card, you must pick the top card on the draw pile. According to UNO, you are only supposed to pick up one card and then lose your turn. But many savage families have the player keep drawing cards until they find one they can play on top of the pile.
10. You can only play a Wild Draw 4 card if you do not have a card in your hand that matches the color in play. If you think a player has put down a Draw 4 card illegally, you can challenge that player and they must show their hand.
11. If you don’t say “UNO” when you have only one card left, and someone challenges you by saying “UNO” first, you must draw cards. According to the official rules, you only have to draw two cards. But some set the penalty much steeper.
12. You can play a Wild card when hit with a Draw 2 or Draw 4 to cancel it and change the color of the pile.
13. 5-Second Rule: A player has only five seconds to make a play, and if they are taking longer than five seconds, anyone may challenge that player and they must draw a card.
14. The dealer chooses a certain number of cards to turn face-up in the deck before each round. Any face-up cards a player gets dealt have to stay face-up in their hand. These face-up cards are still part of their hand and can be played normally.
15. Contrary to an earlier rule, no player may drop an identical card to the one on top of the pile. For example, you cannot play a Red 3 on a Red 3.
16. If a 1 card is played, that player can pass one card to an opponent of their choice.
17. Player names: Each player must pick their game name (can’t be their real name) before play begins. During play, all players have to call all other players by their game name. If they forget and use a player’s real name, one card pick-up penalty.
18. 6 and 9 cards are interchangeable, as are 5 and 2 cards.
19. The one they call the THROWDOWN.
20. Play a 2 and you get to place another card from your hand face-down on top of the draw pile for the next person to pick up. Helpful if your archenemy is two seats down from you and you want to pass a Draw 4 to the person before them in rotation.
21. Play a 0 to force everyone to pass their entire hand to the next person in the rotation.
22. If you have a Wild card, you can play it at any time, even if it isn’t your turn. And you get to pick which player gets the next turn.
23. You cannot end with a Wild as your last card. If you do, you have to draw four.
24. When someone plays a 5 card, everyone must slap the discard pile. The last player to slap must draw 2 cards.
25. Every time you ask if it’s your turn, you draw a card.