Core requirement for Multiboxing:
At the central core of multiboxing we have 3 requirements: 1) the ability to run multiple clients, 2) the ability to send input to those different clients, and 3) some ability to display that.

We used to solve these 3 requirements with software. It was cheap, it was simple to set up, it scaled to obscene levels. And now its been banned.

As we start evaluating new solutions, I think we need to recognize that we are working on meeting 3 distinct requirements. Running the clients and displaying the clients are closely related. But, input control varies greatly. There are different ways to mix and match solution to these 3 core requirements, where making 1 side of this 3-sided equation easier or cheaper may cause more challenges in other areas. The 1st question to ask is how we want to manage input.

Input to Multiple Clients:

There are at least 4 different approaches to send input to multiple clients, and depending on the approach taken this may be broadcast/multicast (sending to all at once), or unicast (sending to 1 at time). With some forethought as to how to rapidly unicast your commands that can approach the speed of broadcasting.


  1. Software Broadcasting – this is what we all used to use. But this has been specifically prohibited now. Some people still keep suggesting other software tools to accomplish this (there are many out there). But if the overall idea is to use any form of software to get input from your mouse or keyboard to multiple clients with only a single keystroke – that’s prohibited no matter what piece of software you use. Don’t do this.
  2. Hardware Broadcasting – this is a bit of a grey area, and its level of acceptability may change if/when we get clarity from Blizzard. The general idea is to use some sort of hardware device to take a single set of input (mouse/keyboard) and simultaneously broadcast those commands out via multiple cables. https://www.amazon.com/gp/product/B07NZSZFL8/ seems to be cheapest tool that people have found so far, but there are others. Note that some people consider this to also be against the “spirit of the law” that Blizzard just implemented and that we should stay away from any broadcast solution. We’ve also discussed possibilities for a DIY keyboard to configure multiple outputs from a single keyboard. No solution yet exists to do this, but it would fall under hardware broadcasting if it has simultaneous output to multiple clients at the same time, and it would fall under keyboard directed below (D) if it only outputs a single keystroke and includes the ability to direct where that input goes.
  3. Mouseover Focus – through simple windows configurations its possible to allow windows to change its focus to where the mouse is, even across multiple physical PCs. This would allow the use to mouse over multiple windows, and provide input to each window sequentially. This approach would likely still be acceptable under even the broadest interpretations of Blizzards software broadcasting rule change because there isn’t any broadcast – its all single input, just moved between windows quickly so that the user can control multiple clients quickly.
  4. Keyboard Directed changes in Focus (aka “Alt-Tab”) – similar in result to mouseover focus, but implemented via keyboard (or perhaps mouse) input, this approach uses a keyboard command to change which window has focus. This is commonly referred to as “alt-tab”, although “alt-esc” or “windows key + <#>” both work better to rapidly advance through different windows. With programable keyboards (or mice) these keyboard shortcuts can be configured to more easily fit along side a typical multiboxers rotation - imagine pressing 1-2-1-2, where what actually happened was to /cast <spell>, advance to next window, /cast <spell>, advance to next window, etc – or even pressing multiple keys at the same (or nearly the same time), where each of those keystrokes included the shortcut to change focus to a specific window & cast 1 in-game ability within that window. Users have also suggested binding “alt-esc” (the “next window” shortcut) to their mouse wheel in order to achieve similar results.


Running and Displaying Multiple Clients:

This is perhaps the easiest to conceptualize, but this also has the biggest impact on what’s required for input


  1. Run multiple clients in different windows on the same physical and logical workstation – connect to 1 or more directly connected monitors, separate window control software is needed (or least very helpful) to size and position multiple client windows. This approach is also easiest to maintain as you are only updating the wow client and addons for a single installation.
  2. Run each client on a different physical (and logical) workstation – this requires the user to either connect to 1 monitor each workstation, or to use Hardware multiplexing tools to combine multiple video inputs into a single display (some 43” monitors have this multiplexing tool built-in)
  3. Run each client on the same physical, but different logical workstations (virtualization), note that are different levels/types of virtualization that each have their own benefits and quirks. Most virtualization software does include software tools to handle displaying of different VM’s within the same monitor.


Combinations:

Once we understand all the different options, we can look at different ways to combine these.

1+_ With any other combination, including C, this is prohibited - don’t do it. Multiple people have suggested that can use the built-in ability on many virtual machine clients to simultaneously connect 1 single keyboard to multiple VM’s. I see this as another prohibited attempt at software broadcasting. I only mention this here to recommend against doing this. It may prove harder for Blizzard to recognize when users do this in VM’s, but I believe this approach violates both the letter of the law and spirit of the law and will get the user banned.

2+A. Does not exist. Conceptually this could be OK (if you’re OK with the concept of hardware broadcasting at all). But no one has yet provided a method for taking the multiple inputs back to a single piece of hardware without either using virtualization, or using other software that already seems problematic. This isn’t to say that someone won’t find/build such a tool, but despite many people looking, no one seems to have found it yet.

2+B. This is the most expensive option up front because you need additional hardware – PC’s and a video multiplexor or additional monitors. This option is only as OK as blizzard is with hardware broadcasting. It certainly functions well (mostly similar with how we used to us software broadcasting), and can scale as large as your hardware allows. This has in-game performance advantages over solutions with mouseover (3) and keyboard directed focus (4) as you’re sending input to all your clients simultaneously. Mistakenly, some people are looking at separate hardware clients (B) in order to try to continue to use a software broadcast (1) tool. Just because you’re using separate hardware does not mean you’re allowed to run broadcast software on those clients separately.

2+C. Using the VM software’s inherent ability to direct each VM to gets its input from a specific USB port, allows the use of a hardware broadcaster (B) to connect to each VM independently. The acceptability of this approach would depend on Blizzards acceptance of “Hardware Broadcasting” vs “Software Broadcasting”, but this may be a cheaper option than 2 + B for most people. It may not be as common for some people to set up multiple VMs instead of multiple VM’s, but its really not any more complex once you get used to it.

3 / 4 + A. This is the cheapest option, for running and displaying multiple clients. Its also the most likely to not be prohibited by Blizzard – it meets both the letter of the law and the spirit of the law. In fact 3 and 4 are the only solutions that meet the “1 input = 1 in-game action on only 1 account” interpretation that many of us are advocating. If you want, you can use 3 and 4 together. But running from a single workstation does restrict your options for input to only unicast input via Mouseover focus or Keyboard directed focus. The more clients you add, the more keystrokes or mouse-overs are required, so there is a practical limit on how many clients you can scale to (up to 4 or 5 should be simple enough for most people, but trying to scale beyond low single digits will get more and more complicated.) This tradeoff will likely be OK for many, but the inability to broadcast/multicast will mean less performance, and less scaling for massive multiboxers.

3 /4 + B /C. While you can run different machines or different VM’s with unified mouseover focus (3) or keyboard directed focus (4) that becomes even more complicated. If you’re OK with a 3 or 4 approach, there’s no advantage to using multiple hardware clients or VM’s instead of a single client. It should be perfectly acceptable by Blizzard, just no reason to do so.

Conclusion:
Different people will approach these challenges differently – some will want the cheapest solution, others will focus on performance, and simplicity will be key for others. Most will find they need to accept some tradeoffs between these. Honestly the in-game control seems fine with 2, 3 or 4. Mostly what we’re missing right now is some polish and refinement. Personally, after starting down a 2+B approach, I’m settling on a 3+4+A solution, but I have friends doing 2 + B and they’re enjoying that as well. I expect that implementation of each of these portions will continue to improve as the community figures out what works and doesn’t work for them.