Wizard of Wor Prototype Discovered: Invisible Monsters

arcadehero March 27, 2017 3
Wizard of Wor Prototype Discovered: Invisible Monsters

(Thanks to Troy F. for sending us details and photos)

If you follow the site on social media then last week you should have heard about our new page dedicated to tracking unreleased arcade games. I’ve always found prototypes and unreleased titles to be interesting and in the arcade business there is a lot of ground to cover with such titles. Thanks to posting about that, another story came up that I didn’t really get into on the site due to other circumstances that has slowed the number of posts we see lately. That story is the discovery of a prototype to Midway’s Wizard of Wor.

The Discovery Of Invisible Monsters

Invisible Monsters arcade cabinet

Every game is a “prototype” until it is released but it is rare that anyone comes across a pre-production version of a game that is fully playable. Wizard of Wor by Bally/Midway is well-known in classic gamer circles, having been released to arcades in 1981 and enjoying some console ports not long after that. It was designed by Tom McHugh and Dave Nutting. If you aren’t familiar with WoW, it is an over-head maze shooter where 1-2 players work to clear out the maze of different creatures, eventually facing the Wizard of Wor. There are numerous maze patterns and while you are supposed to work together, this game had friendly fire so you had to be careful about where you shot. It also was a part of Midway’s games that pioneered the use of digital speech synthesis.

Wizard of Wor Prototype, Invisible Monsters

Not long ago, a Craigslist ad for a strange arcade title called Invisible Monsters popped up on Craigslist in the Chicago area. The buyer who managed to grab it, Troy F., sent us these pictures and also stated what history he was able to find out about it: “The seller’s father was a dentist in Chicago. One day, this guy came in for dental work and couldn’t pay the normal way…but he had some arcades to trade. That’s how it came to be in the sellers family.”

Invisible Monsters Cabinet

It seems plausible that this person who traded arcades for dental work is one of the game’s creators, or just someone who worked at Bally/Midway who ended up with the game.  Back in the early days of arcade gaming, no one really thought about these games being valuable down the road, especially for a game that would end up being improved and mass-produced.

Invisible Monsters Bezel

As for the game itself: “The play of the game is basic and there is no speech. It appears to be a never before seen Mini Cabaret Cabinet. The marquee and cpo say “Invisible Monsters” with Bally midway copyright underneath dated 1980. There are no serial numbers on the cabinet. The ROMs say I.M. in hand written ink. Someone else noticed the unusual cut out where the cpo (control panel overlay) is. This was a two player game…the normal Pacman Cabaret cab didn’t work….so they cut away the sides on the cabinet so 2 people could stand side by side. This is unique to this game only I believe.”

As it is, this is the only known version of this game in existence. Prior to the Craigslist ad, nothing was known about it, including that WoW was originally called Invisible Monsters. Troy is trying to get a hold of Mr. McHugh to get more details about this prototype but so far he has proven very difficult to get a hold of. I’m sure it would be interesting to find out more as to how the concept came about and how it evolved into what Invisible Monsters would become.

A 20 Minute Review & Background on Invisible Monsters

If you prefer videos to reading and pics, then here’s a video by user Mad Conservative that checks the game out in person, showing the differences in how it plays from the eventual WoW release:

What are your thoughts on this discovery?


  1. Trevor March 27, 2017 at 11:11 pm - Reply

    It looks a bit like Beserk. Never saw this before, must be rare.

  2. Neil Brimelow March 28, 2017 at 12:51 am - Reply

    It is interesting to see they developed the initial WOW game using the same hardware as they used on Space Zap, but apparently upgraded the processor for WOW and Gorf to a Z80, thus the bump in graphics from the prototype to the final version. Bally also became Bally/Midway in that next year when WOW was finally released.

  3. AguyinaRPG March 28, 2017 at 7:27 am - Reply

    If you manage to get a hold of Doug McHugh, please be sure to put the word out there. I have been trying as well and I have a lot of things to ask him about.

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