When Nintendo brought out its first game system, the NES, it had a controller with four buttons:

  • Select
  • Start
  • A
  • B

However, somewhere, a designer, in their infinite wisdom, decided that the A and B buttons should not be in alphabetical order. So the B button was placed to the left of the A.

The reasons for this have long puzzled me. Surely the layout is counter-intuitive, and has confused many a gamer.

Can anyone suggest the reason for this design?

NES controller

  • 3
    You might get some answers on this question ux.stackexchange.com/questions/19820/… Short answer is, it doesn't look like anyone knows why they chose the buttons labels they did, and so by reasoning that means we don't know why they ordered them in this manner.
    – JonW
    Commented Feb 13, 2013 at 11:51
  • 4
    I very nearly gave this question +1 just for the nostalgia value.
    – user
    Commented Feb 13, 2013 at 15:03
  • 4
    I've always thought of them as Accelerate and Brake, which then rationalizes positioning them the same as the pedals in a car, but this only applies to racing games...
    – Dani
    Commented Feb 13, 2013 at 17:19
  • 2
    Who's to say that the buttons MUST be in alphabetical order? They're just labels so that people know to push one instead of the other to do a given action. What would be the "right" order for buttons labeled with pictures of a square and a triangle?
    – Andy
    Commented Feb 13, 2013 at 17:45
  • 30
    Traditional Japanese goes top to bottom and right to left...
    – 6502
    Commented Feb 13, 2013 at 18:28

9 Answers 9


I'm guessing they viewed the button on the right hand side as the primary action button as it's closer to the users thumb, with the button on the left for secondary/less-used action, as it's slightly further away from the thumb (more of a physical exertion on the user).

They then may have wanted to label them accordingly - so A for primary button, B for secondary. Perhaps they felt it odd to name the primary button B and the secondary button A.

A-primary B-secondary

does appear more memorable. Maybe it does not matter so much for the physical act of playing but for things like explaining the game moves in instructions or for gamers discussing/explaining moves to friends etc. it probably makes it easier to communicate.

  • 27
    For what it's worth, the XBOX controller has A on the left and B on the right, and it confused the hell out of me when I first used it.
    – Joe Z.
    Commented Feb 13, 2013 at 14:46
  • +1, I've always thought the same thing - not as much reaching
    – Izkata
    Commented Feb 13, 2013 at 14:58
  • 5
    @JoeZeng The "closer to the user's thumb" assumption still applies to the XBOX's reversed arrangement.
    – yoozer8
    Commented Feb 13, 2013 at 16:20
  • I've always thought B (on the XBOX) was closer than A myself.
    – Joe Z.
    Commented Feb 13, 2013 at 16:24
  • Depends how you hold it, I guess. If you consider that the thumb is coming up to the 4 buttons, and A is the lowest, then it is closest. If you look at the thumb coming left, then it's B. Diagonally, though, it's a bit of a toss-up. I feel like I generally use A more, but that obviously depends on the game (and control layout).
    – yoozer8
    Commented Feb 13, 2013 at 18:37

For a definitive answer, I guess you're going to have to track down the original developers of the product.

I would like to make a guess as why this layout was chosen though. I think it is deliberate. I think of the order of the A and B buttons as actions, A being the primary action and the secondary. When holding the controller, you'd want the primary action to be most readily available. When the controller is held in both hands, the A button will be right under the thumb of the right hand. The B button, for the secundary action, would require a little more effort to press and certainly more time to acquire.

  • 1
    I see. Now I think of it, A made Mario jump, while B just made him run :-)
    – Urbycoz
    Commented Feb 13, 2013 at 12:32
  • 1
    @Urbycoz, yeah but who ever played mario without always holding the B button down to run. I don't know anyone that played it with mario just running. Plus, B was used for fireballs. That's a pretty important task. Commented Feb 13, 2013 at 18:54
  • 3
    @JerrySaravia You didn't last very long, or get very far, in Mario without jumping.
    – user
    Commented Feb 14, 2013 at 10:09
  • Of course, then Super Mario World decided to make B the jump button...
    – Joe Z.
    Commented Feb 14, 2013 at 13:35
  • 2
    @Urbycoz important note; it's much easier to hold B and tap A than the other way around, at least in my experience.
    – Zelda
    Commented Feb 14, 2013 at 20:19

It's also worth considering that Japanese gamers read from right to left. So in Japan, the buttons would be in alphabetical order.

What would happen if Nintendo elected to switch the button order for the US market? It seems like that inconsistency would cause way more drama than dealing with buttons that look reversed!

CORRECTION: See Plutor's comment below on why my answer here might not be totally accurate.

  • 14
    This isn't really true. Traditional Japanese is written in columns, from top to bottom and right to left. Modern Japanese is in rows, but those go from left to right. Looking at the original Super Mario Brothers Japanese manual, it looks like they expected gamers to read the latter more comfortably: legendsoflocalization.com/media/super-mario-bros/manuals/…
    – Plutor
    Commented Feb 13, 2013 at 14:01
  • 1
    Hmm, I suppose that's true. Thanks for pointing that out.
    – Mark D
    Commented Feb 13, 2013 at 14:07
  • 4
    "What would happen if Nintendo elected to switch the button order for the US market?" Absolutely nothing. Sony did that ten years later for the Playstation, in a much more internationally-aware market, still does it, and most people don't know.
    – user9739
    Commented Feb 15, 2013 at 15:23

Here's a slightly different hypothesis:

It's not about alphabetically ordering the buttons, it's about their function.

B is for Back and therefore makes more sense on the left.

A is for Accept and therefore makes more sense to be on the right since accepting is a forward or progressive action.

Much the same as Back and Advance buttons on a browser.

Racing games mapped B and A onto the functions Brake and Accelerate - again a natural left and right distinction - braking being a slowing down or backwards motion and accelerating being a natural progressive or forwards (left to right) motion.

Marking the buttons as B and A made it easier to remember which button did what.

Just a hypothesis though...and maybe one that also ties in with the primary action being closer to the right (and therefore more reachable) - since accept and accelerate are conveniently both the primary actions.

  • 2
    Well, it was produced by Nintendo, a Japanese company, so I doubt they put this much thought into a mnemonic system that only makes sense in English. Commented Feb 15, 2013 at 15:38
  • That's probably true since although the NES was release in North America, the earlier Famicon precursor to the NES was a Japanese issue and still had B and A buttons with A at the right. Commented Feb 15, 2013 at 16:17
  • It may not be the original reason, but it may be a reason it stuck. Commented Jun 27, 2013 at 16:06

Take your phone (assuming it's an iPhone or shaped similarly to a controller) and hold it sideways, like this controller.

Assuming you use all four directions of the left hand buttons evenly, and you use A 75% of the time, the controller needs to be evenly balanced when your thumbs are over directions and A. The distance from the side to the center of the direction buttons is roughly equivalent to that of the right side to the A button.

Also, there is more stability and control in general if the hands are spread farther apart. If the buttons were in the center of the controller, it would be less comfortable, as your other hands have nowhere to go.

Secondly, and more importantly, it's easier and more comfortable to move your thumb inward than outward. If you grip the controller ( or your phone ) comfortably and place your thumb over the "A" button, try moving it sideways to an imaginary B button. It's easier to go inward than outward, as the base of your index finger isn't in the way.

It is uncomfortable to move from the A button to the right. This doesn't really change if the buttons were swapped and tested. Even if you had to hold the controller differently, it will feel easier to move in towards the controller than out.

just my thoughts!


Growing up with this system, and the ones that came after, it's perfectly logical to me...

The logic is, "A" comes first, so it's the logical choice to label your "primary action" button. Now, your primary action button is of course the one you press most. Therefore, why not make it the easier of the two buttons to get to, by putting it closer to the edge where you can just mash it with your thumb without worrying about the B button getting in the way?

To be fair, your way of thinking is valid as well, and much more common. The Sega Master system, roughly contemporary to the NES but nowhere near as popular as the NES or its successor the Sega Genesis, has its buttons numbered 1 and 2 from left to right. The Genesis has A, B, and C buttons, again arranged left to right. The PlayStation, of course, never bothered with letters; the x, square, circle and triangle have become ubiquitous. XBox uses letters, with A still in the "home base" position but with B to the right of it at "first base", but more importantly each of the thumb buttons is color-coded so that the in-game icons for each button are very distinct either by shape, color, or both. From what I've seen the colors of each button have been far more important than the letters.

The SNES kept the "A outside" paradigm, but the "ballparked" arrangement of buttons made the B button easier to get to than the A button, and on that system the B button became the "primary action" button for most games, with the Y button (above and to the left) becoming the "secondary action" button, allowing "pad-knuckle rocking" (press B with the first knuckle of the thumb and Y with the pad/tip of the thumb). The A and X buttons were then generally relegated to less common tasks.

The A button returned to prominence on the N64 controller, with the ballpark arrangement tweaked to put A in the coveted "home plate" spot, and the B button above and to the left, allowing the easy "thumb-knuckle rocking" that players had gotten used to with B and Y on the SNES. The GCN kept the focus on the A button, this time by making it the biggest button on the controller (possibly the biggest single button on any stock console controller) but B was still kept on the left. Of course the Wii's controller was a complete paradigm shift to incorporate the pointer/motion-sensing aspect, and the A and B buttons are on completely opposite sides of the thing.

It's notable that when the Wii-mote is held sideways and used "platform" or "racing"-style (not the most comfortable arrangement by any means, but passable especially when using a shell like the Wii Wheel or BOSS), the buttons pressed by the right thumb are the "1" and "2" buttons, and are arranged left to right. So it took 20 years, but Nintendo did eventually get with the program in this small way. The plug-in "Classic Controller", however, reverts to the SNES layout with B at "home plate" and A at "first base" (even though many of the games it's used to play, like NES Virtual Console games, use A as the default primary action button).


While understanding the logical thought @André points out I would like to point a flaw in this thought process.

If I were to calculate the amount of time my B is pressed vs A in this topics chosen 'Go-to-Game' of I would conclude that B is my Primary. Also, 'B just made him run' should be 'B saves your life'.

I would raise an arguement of 'That is just what happened' If I think about it from a perspective of making a video game program in a market that was remotely fresh I would imagine a group working hard to get functionality down. In the attempt of creating a working model naming something button A and button B would not be unheard of. They may have even had them switched initially and liked the simplicity and universal usage of these names. They may have originally had A on the left but through a mass production wiring mistake they had to switch the painting of the controllers. Given all the possible reasons, to me the most likely is it was a happy accident.

However, this does open up other questions like why they chose to use X Y and not Y Z for the SNES.
Why was a select button even created when there was an ability to use the directional pad for user selection?

  • The N64 had a "Z" button. Maybe they had that in mind, when designing the SNES.
    – Urbycoz
    Commented Feb 13, 2013 at 15:15
  • It doesn't follow the pattern. I would accept the logic creating Y Z then implementing both C and X in the future.
    – o0Kvothe0o
    Commented Feb 13, 2013 at 15:28
  • 2
    Perhaps X and Y are more memorable as Cartesian coordinates or algebraic variables.
    – Joe Z.
    Commented Feb 13, 2013 at 15:47

They're actually not round the wrong way (from a usage perspective)...

Typically, you use a controller with both hands so expected usage is for the left hand to cover the left hand side controls on the controller and the right hand to cover the right size controls on the controller.

This means that the left hand is working left to right (ltr) and subsequently the right hand is working right to left (rtl) in terms of thumb access. Making it A then B from the right hand side.

This subsequently reinforces Spiral13's answer in that the A button is considered the primary action button which is closer to the hand controlling the controls on the right hand side of the controller.


Funny cause I remember as a small child in the late 80's having that grey, black, n' red controller in my hand and my very first thought was "This is so cool! I love it! I wanna play the Ninja Turtle game, that has to ovbiously be the best game in their library (. . .it wasn't, not even close lol) ..but I convinced myself it was being such a biased TMNT fan, even after all the deaths and continues wasted I still was just excited I could be Raphael. NOW.. my second thought always was more like a pet peeve of mine which was "Why is this backwards. Do they have any other controllers on the market with A-B instead of this B-A stuff. I don't like it, it's backwards. How they mess this up?" It really annoyed me. I thought that if I was just a child that could understand that A comes before B that ANY adult should easily understand simple Alphabet as well, especially an adult who specializes in building these gorgeous plug in your TV and play fun machines. Anyhow I eventually got over it, especially around 1992 when I got my Gameboy (The Big Grey OG). I actually started to see it as a cool thing. Like, yeah we know it's backwards . . .what's your point? I thought of it almost like one of their many iconic trademarks..

Sooo WHY did they do this??? Honest answer is that I don't know and I've dug around looking for info on it but NEVER found out. But my idea was.. Japan sometimes has books, manga, comics, newspapers that you read from Right to Left while we (speaking for the USA) read from Left to Right. That being said.. for sometime I believed that they flipped the letters because of their traditional writhing format called Tategaki. That being said MAYBE because they write things differently maybe they also marked our devices backwards.

But again.. this isn't fact, just one of my THOUGHTS. I do NOT know why they mark their systems controllers B to A instead of A to B.

Good luck, and let me know if you all ever get a definitive answer. I'll love to know personally. -Russell

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    Commented Sep 20, 2020 at 17:07

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