How Do Challenges Work in UNO? (3+ Challenges to Know About!)

Remember the good old days when we played carefree Uno with our family? Then we grew up, and suddenly, new Uno rules came up. We have all been there. I learned to play Uno as a kid, so I assumed I knew all the rules. Watching my kids play, I learned I was wrong. There are challenges.

UNO allows for challenges when one player thinks another played an illegal card. The challenger must state their accusation. The player must prove their play.

  • If the move was legal, then the challenger gets a penalty.
  • If the move was illegal, the player incurs a penalty.
  • Unchallenged illegal moves happen, and nobody incurs penalties.

As it turns out, Uno is much more than a simple matching card game. Just match the card with the top card on the pile, get rid of all the cards, shout “Uno,” and the game is over. Or is it? Read on to find out.

An image of Friends sitting at the table and playing cards.

What Is a UNO Challenge?

The Uno Challenge rule allows a player to ask another player to show their cards – if the first player has a hunch that the other player played a card illegally. The challenge also penalizes whichever player was wrong.

Players mainly apply this rule to the wild draw four cards because those are only supposed to be played if you don’t have the current color card (on the discard pile) in your hand.

But, there are other Uno challenges we may not have heard of before. So, let’s get started!

Challenge #1: Uno

If the player did not call “Uno” when left with one card in their hand, we could challenge them, and in that case, the player has to draw two cards.

As a kid, my favorite thing to do in UNO was to make it look like I had only one card – and that I’d forgotten to call UNO. Then, someone would challenge me. I’d happily flash my multiple cards at them and watch them draw two cards while scowling at me.

Challenge #2: Wild Draw Four cards

If we’re given a wild draw 4 card by the previous player, we can challenge that player (if we think they played a wild draw four card illegally).

Then, the player must show us their cards, but only we (the challenger) get to see them.

  • If the player is guilty, they will have to draw four cards.
  • If the challenger is wrong, we must draw four cards plus two more.

When can I challenge the wild draw four cards?

The only person who can challenge a wild draw 4 card play is the person who would have to draw the 4 cards.

So if you are any other player, you can’t challenge the draw 4 card. On the plus side, you aren’t on the hook for drawing 4, the challenge, or the penalty.

What happens after you challenge the wild draw four cards?

When someone decides to challenge the player next to them, they have to show them their cards. If it turns out the player is guilty, they draw four cards as a penalty. The accuser must draw six cards in total if the challenged player is innocent. 

Why six cards? Players draw this amount because the wild draw four card is in effect, and the additional two cards are a penalty for accusing the player incorrectly. So, it turns out Uno is a harsh game, after all.

Illegal play of a wild draw four card

Regular cards and action cards in Uno can be played at any time, except for the wild draw four cards. We can only play this card if we don’t have any other matching cards to lay down.

What does an illegal wild draw four card mean? This is the most asked question, so here is the answer.

For example, we have two cards: a yellow seven and a wild draw four. It is our turn to play. The facing card is also yellow. The next player has one card left in their hand, which means they might win.

We might think it would be a great strategic move to play a wild draw four card against a player. This way, we have the best chance of winning the game. Well, not exactly.

Official Uno Challenge rules say if a player has a matching card (in this case, a yellow card) in their hand, they must play it. If we don’t have a matching card, we can only play the wild draw four card.

No one can see the cards in our hands, right? So, what could possibly go wrong? But we didn’t expect the player next to us to submit a challenge, so we had to show them our cards.

So in this particular situation, the safe play is the yellow 7 card. That doesn’t mean we can’t play the wild draw 4; playing that card is possible but risky. If we play it, we risk getting challenged. However, there’s also a chance the play goes unnoticed and unchallenged.

And just like that, UNO goes from a game of chance to a game of skill!

Challenge #3: Other Uno Rules

Uno seems like a very simple card game, and it is. But that doesn’t mean it has no challenges for the players. Here is a rule you probably don’t know about.

Stacking cards

Stacking special cards, like drawing two and four cards, isn’t allowed by the official Uno rules. But hey, rules are meant to be broken. Stacking is one of the most popular adjusted house rules.

And if you don’t get caught or challenged? It’s totally allowed, right?

Uno flip challenges

We’re free to challenge the player if we illegally play the wild draw two cards. The player must show us their cards. If they are guilty, they must draw two cards as a penalty.

An image of Text GAME TIME spelled out in wooden letter. Surrounded by dice, dominoes uno playing cards on black.

How Does Uno Challenge Work in Uno Online?

Uno rules are the same if played online, which means the challenge rules work the same as the physical card game.

We can play Uno online with our friends and family thanks to technology. Of course, nothing beats the actual cards in our hands and the atmosphere, but if there is no other choice, this is the next best thing.

Well, unless it’s not feasible to have cards, or we’re playing with friends who are far away. Or if our local friends don’t like playing UNO with us, we have to play online. Then the online version is the best option!

If we suspect an online player played the wild draw four cards illegally, we can challenge them. If the player is guilty, they must draw four cards. If the online player is innocent, we must draw six cards.

When challenging “Uno“ to another online player, tap the word “Uno.” Otherwise, you will have to draw two cards as a penalty.

Key Takeaways and Next Steps

The Uno challenge rules are not very well-known among players, which is fine. We only learned about it a couple of months ago when the kids were reading the UNO rules because we were knee-deep in cooking dinner.

The wild draw four card challenge rule is the most mysterious for people. We interpret the game rules in our own way. It seems like every family has its own set of rules.

I freely admit, until recently, I was unaware of this rule. But the beauty of Uno is that we can make our “own rules.” Why not? Also, I enjoy nothing more than stacking draw two or four cards. I admit I am one of those people.

Perhaps we have all played Uno the wrong way. But people love playing Uno because the rules can be modified. The wild draw four card challenge is exciting. We can exercise our poker faces! It makes the game more interesting and fun. What do you think?

We hope you have enjoyed this article about how challenges work in Uno. There are lots of ways to play Uno. The articles below have a few new ways to play this fun game, so check them out.

If you’ve never made your own rules in UNO before, you don’t know what you’re missing. Read the custom UNO variations article listed above – and I’ll share my favorite variations with you there. See you there!

An image of Children playing cards outdoors.


Learning from your own experience is important, but learning from others is also smart. These are the sources used in this article and our research to be more informed as gamers.

  • “Enjoy4fun Uno Online.” Enjoy4fun, Accessed 27 Sept. 2022.
  • Feinstein, P. “The Crazy UNO Rule We Bet You Never Knew About.” Reader’s Digest, 22 Feb. 2018,
  • How Do You Win a +4 Challenge? – Uno Q&a for Wii – GameFAQs. 25 Jan. 2010,
  • UNO rules. Mattel, Accessed 7 Oct. 2022.
  • UNO FLIP! rules. Mattel, Accessed 7 Oct. 2022.

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