Can I (safely) assume that people playing my game have a middle mouse button?

The title pretty much says it all.

I am currently writing a desktop game, which will probably not be played by the casual gamer. Thus my expectation is that nearly every user will most likely already have a mouse with a scroll wheel + button. Is that true?

This question is for "gamers" - I don't care if my grandmother's laptop doesn't have that button.

(Of course I know that I should think about a system that allows to change the input settings to make the game playable - even without a third mouse button.)

• Expect some bad reviews if you can't change the controls in a desktop pc game. – János Turánszki Dec 27 '14 at 11:48
• Many mice have scroll wheels which are hard to use as a middle mouse button without also accidentally scrolling in one or the other direction - you might want to make sure the player can't screw up that way. – Philipp Dec 27 '14 at 12:01
• I play the majority of my games on a machine with only one mouse button. You cannot even assume we have 2 mouse buttons, much less a middle one. You might consider allowing some arbitrary l-button + keyboard combination to do what you are trying to do with the 3rd mouse button. I use Fn + Primary Mouse button as an alias for right click in my own software. A lot of gamers will have some 3rd party software setup that does this sort of thing, but I prefer to support it directly in my own software. – Andon M. Coleman Dec 27 '14 at 12:53
• I have a computer with no middle mouse button, make of that what you will. – Thijser Dec 27 '14 at 22:30
• Since you target actual gamers, then imo, yes!. Assume that. Although as others mentioned, gamers would also expect customizable controls, more so than casual game-playing audience. – MasterMastic Dec 29 '14 at 7:02

Although you are targeting desktops, there will be players on (gaming) laptops and for some of them, it will be an inconvenience to get a mouse before being able to play your game. It would sound like a good thing to me, if you were to support alternative control schemes or customizable controls.

This is not a very "sciency" answer - I've just run into this problem a lot with games and tools I developed. My experience might not reflect the one you are about to acquire, so feel free to disregard this advice.

• PC user here. I use Wacom tablet. No middle button here as well. – Kromster Dec 27 '14 at 14:53
• In touchpads, usually clicking both buttons together means MMB – Kroltan Dec 27 '14 at 15:40
• @Kroltan If anything I'd say that'd be worse for gaming; since it means you lose the ability to do left/right button combos (eg holding a button down for move to cursor and clicking the other to shoot). – Dan Neely Dec 27 '14 at 17:23
• @DanNeely I know. It's a touchpad feature, not the games that do that: if you press both buttons at the same time, it counts as MMB. If you press them separately, it will not, even if both are down at the same time. – Kroltan Dec 27 '14 at 17:40
• @Kroltan I keep hearing about it, but I've yet to actually own a touchpad that does that. Far from a safe assumption. (Yes, there's third-party software that emulates it. Unless you're build that into the game...) – Bob Dec 28 '14 at 7:23

It really depends what you mean by "assume". Are you making this assumption at the point of designing your gameplay mechanics? Or at the point of deciding whether or not to implement fully customizable key bindings?

You could mean "I assume real gamers have a 3 button mouse, therefore I don't need to offer the option to rebind bayonet-thrust to a keyboard button". If you think this you are wrong. Always, always wrong. I personally have my peculiarities when it comes to input configuration, as will a sizable chunk of your player base. E.g. I started playing FPS games when I was much younger and my left little finger struggled with the default crouch/sprint arrangement. I swapped them and got used to them being swapped. I will always resent games that lack this option to rebind. I also weirdly expect "up" to mean "up" with a mouse, but with a controller I like it to mean "up" in first-person and "down" in third person. Games that let me configure these separately give me a warm glow. Games that don't give me the option better not have me switching between the two during an action sequence (e.g. 3rd melee, 1st person iron-sights), or I'll find myself looking at my feet or the sky as the action plays out around me.

However, you could easily mean: "I assume a middle mouse button exists when deciding that there will be 3 unique actions my player can execute at a full run, while comfortably strafing either left or RIGHT" If this is going to be true of your game then rebinding MMB to a keyboard button is an option (and you really should offer the option), but probably not an ideal option. I strongly feel that in this situation you should assume that your players will have the appropriate equipment, rather than hamstring your gameplay mechanics. Certain games will always suit certain input methods better than others. Imagine if the Assassin's Creed series had cut out any gameplay mechanics that wouldn't have played equally well on a trackpad.

To sum up: don't compromise on gameplay, but offer every configuration option you can imagine.

• +1 I always remap my games to use WAXD instead of WASD because I once mapped my emulators to use WAXD because I found it more akin to a D-pad and got used to it. It annoys me when games don't let you remap WASD, suffice to say that either way I don't play many of those. – Pharap Dec 29 '14 at 10:45
• @Pharap So you use your index finger to hit X? That would make it hard to strafe/turn right (D) while going backwards. I would think WAZD would be easier if you want to use the same finger for W and Z. – bcrist Dec 30 '14 at 15:52
• @bcrist Point is, personal preferences are subjective, important and unpredictable. So make sure your controls are configurable. – Schwern Dec 30 '14 at 17:48
• @bcrist No, I use my thumb for X. One finger (digit?) on each direction at all times. S is then usually crouch or sprint, and thumb moves down to jump, followed by a ton of edge cases. It might seem odd, but that's just because most people are used to WASD, which really bothers me. It's like trying to write with my non-writing hand. – Pharap Dec 30 '14 at 18:28
• @Pharap Ah, that makes a lot more sense. I might have to try that sometime. Most games disincentivise significant backwards movement, but in a game like Kerbal space program where you often go quickly and repeatedly between W and S it could be very useful. – bcrist Dec 30 '14 at 23:16

Many laptops lack a middle button, especially those with a trackpad, and you need special software to emulate it.

Mac laptops have only one button. Right-click is pretty easy (two finger click) and not uncommon in Mac games, and the two finger drag to scroll isn't bad, but only in slower paced games. However, there is no concept of a middle click in the Mac Trackpad system settings. You need special software.

You might say "who cares about laptops, nobody games on a laptop". The Steam Hardware & Software Survey is a wealth of information about what people actually use. 70% of the Mac users on Steam are using a laptop. PC laptop gamers are harder to track, but you can get an idea by looking at the video cards and noting the mobile ones (GeForce blah blahM, Intel HD Graphics, "Mobility", and "Mobile"). By my reckoning that's 30% of the market.

For example, I have a custom built desktop PC at home for gaming with a five button Logitech gaming mouse. Tomorrow I will get on a seven hour flight. I will have my Macbook Pro laptop and 200+ Steam and GOG games to choose from. I will not have room on the tray for a mouse. The games I will be playing will be ones which work well with a trackpad.

Absolutely allow all of your controls to be reconfigured. Even if people have the buttons, there will be people who will not like your default controls. It's such a small thing to avoid your customers getting frustrated.

FWIW I generally avoid the middle mouse button because it can trigger the scroll wheel. I also avoid the scroll wheel to switch weapons because I find it slow in games with more than two choices. For something like a melee attack or crouch, I typically use F or a thumb side button.

• With BootCamp, you can't exclude MacBooks as a viable gaming platform even if your game is Windows-only; a Mac user has but to reboot into Windows, and then find themselves without a middle-click in your game. – Doktor J Dec 29 '14 at 23:24

Some people use a trackball (some trackballs have no middle mouse button), trackballs generally are just as good pointing devices for players as ordinary mouses.

The trackball I linked has no middle mouse button, and (at least on Windows) has an unusable scrollbar; despite these shortcomings I managed to finish quite few action games using it ;).

Even if I do have a middle mouse button, its awkward to click. I personally would not ever want to use it for anything other than scrolling. Also, speaking from experience, having the middle mouse button be set as scrolling/zooming has also caused me grief in the past. There was a game that I played (called Rappelz in case anyone is curious) in which the middle mouse button was the only control set to zoom in/out. I used to play with a mouse without such a wheel, and several times the game changed the zoom without me knowing why, and it was quite an annoyance trying to fix it afterwards.

TLDR: In my opinion, using the middle mouse button is not a good idea

I would certainly include a controller customization screen in the settings of the game. Even though you noted that you are aware of a controller-customization system, I think it is the correct way to do this and it is the answer to your question.

I would quickly make a customization class and assign the keys by code (initially/harcoded), so I could just continue developing the game without losing time. Later I can get back to the customization class to create a UI.