ZZT

ZZT
Developer: Tim Sweeney Publishers: Potomac Computer Systems (pre-v3.1), Epic MegaGames (v3.1 onward) Platform: DOS Released in US: January 15, 1991 This game has unused areas. This game has unused sounds. This game has debugging material. This game has revisional differences. This game has a development article This game has a bugs page

Before Gears of War, before Unreal, before even Jazz Jackrabbit, there was ZZT - an action-adventure puzzle game which looked dated on release, but managed to sell enough copies to help fund the development of Jill of the Jungle, spawn a much less successful sequel, and attract a small community of hobbyist world creators that continues to this day.

While the game enjoys a significant collection of fan-created worlds, this article covers only the content officially released by Potomac/Epic MegaGames:

• The ZZT software and its revisions.
• The "four official worlds": the shareware Town of ZZT, as well as the registered-exclusive Caves of ZZT, City of ZZT, and Dungeons of ZZT.
• The additional bundled worlds: Demo and Guided Tour of ZZT.
• The shareware bonus world compilation Best of ZZT, consisting of two separate worlds: The Secret of Headhunter Isle and The Royal Treasures.
• The shareware bonus world compilation ZZT's Revenge, containing The Crypt, Darbytown, Ezanya, Fantasy, Mystery Manor, and Smiley Guy.

Sub-Page

Development Info

Bugs

Cheat Codes

ZZT comes with a built-in cheat console. To access it, press the ? key (during gameplay or in the editor) or the | key (on the title screen). Versions of ZZT before v3.2 require setting the DEBUG flag before cheats are available, as well as writing the cheats themselves in lowercase.

Available cheats are as follows:

• zap - Clears the four spaces surrounding the player. Be warned that this removes everything in those four spaces, including objects critical to the game, which can (and usually does) render games unbeatable.
• keys - Gives the player all 7 keys.
• ammo - Gives the player 5 ammo units.
• gems - Gives the player 5 gems, but not the corresponding 5 health units one would receive by picking up the gems in-world.
• torches - Gives the player 3 torches.
• health - Gives the player 50 health.
• time - For time-limited boards, adds 30 seconds of extra time.
• dark - Makes the room dark.
• -dark (v3.2 only) - Removes the darkness attribute.

Typing in + or - followed by the name of a flag will set or clear that flag. This functionality is occasionally used by fan-created game worlds to provide additional inputs, such as a help menu or inventory system.

Debug Mode

In order to activate debug mode, set the DEBUG flag by typing +DEBUG in the cheat console. This has the following effects:

• In versions of ZZT prior to v3.2, cheats are only made available when debug mode is enabled.
• During gameplay, the "m" followed by some numbers is shown on-screen where the cheat console appears. This value is the number of bytes remaining in heap memory for objects on the current board and the entire compressed data for the game world being played.
• Save files can be edited and played. As a side effect, quitting and restarting a world will not restart it from the beginning.

World Locking

ZZT provides an official way of protecting worlds from being examined in the editor - any world saved with the SECRET flag set will qualify as such. The following official worlds are locked using this method: Town of ZZT, City of ZZT, Dungeons of ZZT, and Guided Tour of ZZT.

Notably, the official world Caves of ZZT is not among them. When this method was reverse engineered by the community in early 1990s, many fan-created worlds adopted it; later, more advanced editing protection techniques were developed, which typically relied on engine flaws.

In ZZT v3.2, games locked using this method can be opened if the editor is used with debug mode enabled.

Revisional Differences

Being a game distributed on PC via BBSes and floppy disks makes it easy to create new revisions. The community has managed to preserve a substantial number of them.

• Versions of ZZT released by Potomac Computer Systems (later Epic MegaGames):
  • ZZT 2.0
  • ZZT 2.0 (Registered) - contains a few minor bugfixes over the shareware release. All future releases would use the same executable for shareware and registered versions.
  • ZZT 3.0 - released around June 1991.
  • ZZT 3.1 (September 1991 build) - a build of unclear origin discovered in late 2020.
  • ZZT 3.1 - released around November 1991.
  • ZZT 3.2 (March 1992 build) - included alongside ZZT's Revenge.
  • ZZT 3.2 - the final version, released around May-June 1992.
• Versions of ZZT released by SoftDisk Publishing under a sub-license:
  • Worlds of ZZT 3.56 - based off ZZT v3.0 and released in late 1991. Bundled with ZZT's City, a modified version of City of ZZT,
  • Worlds of ZZT 3.57 - released in 1994. Bundled with ZZT's Town, a modified version of Town of ZZT.

Configuration Screen

v2.0	v3.0

v3.1	v3.2

• Visual changes:
  • v3.0 changed the text layout and made the configuration screen much more colorful. In registered builds, it also no longer shows the registrant's name.
  • v3.1 (not the September build) changed the copyright holder's name to Epic MegaGames.
  • v3.2 keeps the general layout of v3.0/v3.1, but adopts a black background again. Also worth noting is the disappearance of the "The Object Oriented Game" subtitle. Finally, in v3.0 and above pressing ESC at this screen allows you to exit ZZT without finishing the configuration process.
• Functional changes:
  • v2.0 only reads configuration information from a special REGISTER file for registered versions.
  • v3.0 supports saving configuration information in the form of a ZZT.CFG file. You can force reconfiguration by launching ZZT with the /R parameter.
  • v3.1's later build does not support configuration files at all. As such, this version will always identify as "shareware".
  • v3.2 restores a ZZT.CFG file. However, it now only stores the name of the starting world and a registration flag.

Worlds of ZZT v3.56	Worlds of ZZT v3.57

SoftDisk's Worlds of ZZT adopts a different color scheme than any version of ZZT v3.x, but preserves its general layout. Copyright dates are adjusted accordingly, and the SoftDisk phone number is omitted from v3.57.

Other Differences m

• Pre-ZZT 2.0
  • As indicated by the Demo world, Water was a different color - blinking white on blue - at some point before being changed to v2.0's blinking blue on light gray.
• ZZT 3.2
  • The ability to shoot by using the space bar has been added, but only in the final May/June 1992 build.
• Worlds of ZZT 3.56 (relative to ZZT 3.0)
  • The editor has been removed.
  • Instead of using the /R parameter to force reconfiguration, /C is used.
  • The ?AMMO cheat grants 15 ammo instead of 5.
  • The "Pausing..." text, as well as the "Play" option in the title screen, are made blinking.
  • The cheat console can no longer be entered from the title screen.

World: Town of ZZT

To do: Document the gameplay changes, if any, introduced in the Worlds of ZZT version.

v2.0	v3.0

v3.1/v3.2	Worlds of ZZT v3.57

With v3.0, the title screen received visual tweaks. v3.1/v3.2 is similar to what came before, but features the Epic MegaGames branding and makes it more clear that there were additional game worlds in the series available.

The SoftDisk version, interestingly, mixes the visual layouts of v2.0 and v3.x.

World: Caves of ZZT

v2.0	v3.2

The title screen and first board received visual tweaks between v2.0 and v3.2.

World: City of ZZT

To do: Document the gameplay changes introduced in the Worlds of ZZT version.

v3.2	Worlds of ZZT v3.56

The SoftDisk version redesigned the title screen.

World: Guided Tour of ZZT

v2.0	v3.0+

v2.0's bundled version of the Guided Tour of ZZT presented, among others, the board "Pac-Man" from Caves of ZZT. In v3.0 and above, this has been replaced with a board from City of ZZT.

Unused Content

Unused content in ZZT worlds can be observed in a few ways:

• Looking for unused objects, object labels never called, called object labels which don't actually exist, or commented out code.
• Analyzing Empties - when using the official editor, clearing an element with an Empty does not clear the color information of the previously placed element. This allows discovering some types of changes to board layouts, as well as removed Text - as a Text element stores the character of the Text in the color information.

Unused Sounds

Bank Vault (Start)	Bank Vault (Failure)	Bank Vault (Success)

Town of ZZT features commented-out sound effects for trying to open the Bank Vault, with different tunes for starting the opening process, a successful open, and a failure. Notably, the duration of the opening process melody is much longer than the duration of the final Bank Vault's process.

Empty Boards

The editor does not provide any way to delete boards entirely; as such, if a world creator wanted to remove a board, they had to either repurpose it or clear its contents. As such, many worlds would end up having "unused", empty boards, which act as a suggestion of something having been scrapped. These are not accessible in normal gameplay.

• Town of ZZT contains a board named "-unused" whose contents are entirely empty, not even the yellow border that traditionally accompanies a newly-started ZZT board.
• Similar boards also exist in Caves of ZZT, Dungeons of ZZT, and Darbytown.
• Guided Tour of ZZT contains a similarly unused board called "g", which does have the yellow border.

Notably, the second of the two unused boards in Caves of ZZT contains Empties whose colors suggest that some work had been done on this board, only to be later cleared.

Scrapped World Name?

The official worlds all have special entries in the world list which give their full name. In v2.0, creating a world called PHYSICS.ZZT will result in the full title "The Physics Behind ZZT" being displayed. This is not present in later versions, and suggests an official world went unreleased.