YMMV / Uno

• Accidental Nightmare Fuel: The Uno Attack commercial. The Card launcher comes to life, and it looks really cursed with the cheesy CGI and the slug-like design.
• Common Knowledge:
  • Going by Memetic Mutation alone, you'd assume the Reverse card can be played on a Draw or Skip card to apply that card's effect to the player who played it. While there is a Popular Game Variant for that, officially, all the card does is reverse the order of turns.
  • Most people assume that if you don't have a match, you draw until you get a matching card. This is another Popular Game Variant usually labeled "Draw to Match" (and contributes heavily to the game's reputation for going on forever); in the official rules, you only draw 1 card, which leads to generally shorter games.
• Ending Fatigue:
  • Reaching 500 points is already a daunting task, but a single round can take just as long as most Action Cards tend to skip players. Playing with "Progressive Uno" (where Draw 2s and Wild Draw 4s can stack) or "Draw to Match" (players must draw cards until they have a match) adds more cards to players and more time to complete.
    • You can deliberately invoke this with the Customizable Wild Cards by making players draw more cards.
  • A round of Dos can end with everyone not having the matching number card and often results in a cluttered center row until one player is able to match and then win.
    • Dos for the most part however, seems to invert this. Due to the ability to match and play multiple cards, rounds tends to last no more than 5 minutes. It's even possible to win on your first turn if there's are at least three cards and your hand allows for color matching.^ExampleAssuming you still have seven cards, double matching two of center row cards then single matching the third card leaves you with two cards and two bonus discards, allowing you to win the round.
    • Even playing with points, its very easy to hit 200 points due to the reason above. You can even win in a single round of Dos if its in the very beginning of the game, you happen to have a lucky hand, and the center row allows you to make two double color matches.
• First Installment Wins:
  • In terms of physical gimmicks, Uno Attack has been in stock and updated since its debut. Uno Spin, the second installment, got reduced to a "Travel" form before slowly fading out.
  • Uno continues to be played to this day. Its sequel Dos has a difficult time catching up due to its complex rules and the lack of any attacking cards.
• Hilarious in Hindsight: In Mattel's 2022 Updated Re-release of ONO 99, the Reverse Card was buffed to reflect the Double Play attack card back to the user, just how the memes portrayed it as. For bonus points, the cards were redesigned to look like Uno cards.
• It's Easy, So It Sucks!: Uno All Wild! can be this, as while every card is legal at any time, there aren't many Action card types to substantially affect gameplay.
• It's Short, So It Sucks!: Dos has the common complaint for being too short for the reasons stated above.
• Memetic Mutation:
  • Treating the game as Serious Business or as a Family/Friendship killer.
  • The Wild Draw Four showing up in other tabletop games. Similarly, Uno cards appearing as magical entities.
  • Uno Reverse Card/NO U^ExplanationThe Reverse Card is often used to represent a comeback or a turn of events. Like telling someone "No, You".
  • The Custom Wild Cards often having absurd rules, most commonly forcing the next player to "Pick up the whole deck".
    • [an undesirable action] OR draw 25◊^ExplanationA meme that popped up in early January 2020, with the joke being Exactly What It Says on the Tin: someone holding a Custom Wild Card with two options on it: an undesirable action, or Draw 25, followed by an image of the person holding a lot of cards. Can be used as a Take That! towards people or groups, or just for humor.
  • The presumed next game of the series being called "Tres" (3) to keep up with the counting theme Dos (2) started.
  • YOU HAVE UNO!^ExplanationA heated argument between two online friends on whether one of them has Uno on their Xbox 360 as early consoles had it preinstalled. The Fire Emblem: Three Houses fan gag support conversation based on this also spawned a meme upon the game's fanbase with Uno always being related to the characters Marianne and Hilda in fanworks.
    • Complete with two Neon Genesis Evangelion versions.
    • As well as a Resident Evil Village version.
    • And a Castlevania: Symphony of the Night version. Which also has an animated version.
    • And now a Sonic Adventure 2 version.
    • And a Metal Gear Rising: Revengeance version.
• Popular Game Variant: Some house rules are so common that they have displaced the real rules to many players. Most people don't play with the official rules, to the extent that they won't even announce which house rule sets they play with when the game begins.
  • Omitting the 500-point goal. Most players just want to shed cards, so they ignore this and just declare the first player to get rid of their cards the winner. The remaining players may or may not keep playing for 2nd, 3rd, etc. The game and its spin-offs would update its rules in 2022 to officially make this the main victory method while downgrading the point goal as an optional rule.
  • Allowing a Draw Four to be played at any time. The official rules state that you can't play one if you have another card in your hand that matches the color on the discard pile (or a regular Wild card, per modern rules), and that the next player can challenge a Draw Four play. If someone gets busted for an illegal Draw Four play, they have to draw four instead... but if the play turns out to be legal, the challenger faces a six-card penalty. Many players ignore this bluffing rule because they don't like it or aren't aware that it exists.
  • Allowing Draw Two/Draw Four cards to be stacked. In the official rules, you'd just simply draw the cards and lose your turn. The house rule lets you avoid doing so by stacking another card on top of it, forcing the next person to draw the cumulative number of cards unless they can add to the pile.
  • Players only draw one card if they have no match. A house rule (known as "Draw-to-Match" in the Ubisoft game) is for a player to keep drawing cards until a matching card is available.
  • There's a rule in some households that in addition to shouting "UNO!" when you're down to your last card, you must also shout "UNO OUT!" when playing your final card, else you get penalized in a similar manner to not shouting "UNO!" This is not part of the official rulebook, but enough households swear by this unofficial rule that it led to an entire debate on Twitter when NBA player Donavan Mitchell asked the question of whether or not the rule was official to his followers.
• Spiritual Successor: To Crazy Eights. Apparently Uno was created because Merle Robbins and his son had an argument over the rules of Crazy Eights.
• That One Attack: The Wild Draw Four. You pick up four cards and lose your turn when your opponent is successful or unchallenged. If you use the card and the next player challenges you, then you have to show your cards to them to prove you didn't cheat. The card reveal and players being mostly honest are the reasons why most people don't bother challenging Draw Fours or omit the rule altogether.