The Development of Doom's Status Bar

Background

During the heyday of DOS platform scrollers in the early 1990s, the information conveyed on the screen for the player varied wildly from one game to another. Some titles like Duke Nukem (1991) cordoned off an entire third of the screen for score, health, and inventory readouts. By contrast, Id's 1990 Commander Keen trilogy had no status panel or heads-up display at all: To avoid player distraction, the game sequestered this information in a popup engaged with the space key.

Commander Keen: Goodbye Galaxy! (1991) straddled both worlds with its innovative approach. The game featured a small non-distracting corner readout with essential gameplay information, and a more detailed hotkey-engaged popup.

The first "3D" games were somewhat regressive graphically and coincided with a trend towards greater UI standardization, with status displays migrating towards the bottom of the screen. Doom's direct progenitor, Wolfenstein 3D (1992), had an always-visible status bar with the following elements:

Level designator.
Score tally.
Lives tally.
Health tally (conveyed by both a percentage, and a graphical representation of the player's injuries).
Ammunition tally.
Keys in inventory.
Weapon selected.

In the end, a similar status bar made its way to Doom. But the UI took many tortuous twists and turns to get there.

First status bar: February 1993.

Id Creative Director Tom Hall sensed that Doom was destined to change existing paradigms of design. His 1992 "Doom Bible" laid the foundation for an ambitious game...almost too ambitious a game for a small team to actually deliver, as many of the features spelled out for inclusion (cinematic cutscenes, sonar, shape-changing walls, computers displaying messages, and playable characters) failed to make the cut in the end.

The status "bar" in Doom's earliest development alphas may have also been a little too ambitious. It took on the appearance of a helmet visor, crowding the player's view and bombarding them with information on three sides. Its first documented appearance was as a mock-up in Doom: Evil Unleashed Tech Demo "0.2," dated 1993-02-04.

The display contained the following elements:

Upper left: Weapon.

Too much information is provided: A weapon title, a weapon silhouette (carried over from Wolfenstein 3D); information about "DAM" (damage), maximum magazine size ("MAX"), rounds per second ("RPS"), a statistic of unknown significance ("RNG"), and an ammunition tally. The circle-triangle symbol was intended as the in-universe logo for the United Aerospace Armed Forces, the military-industrial group that employs the protagonist.

Although the status panels in Doom 0.2 are a non-interactive mock-up, the executable contains the titles and graphics of additional weapons intended for on-screen display. These jibe with proposals from the "Doom Bible," and are as follows:

Knife. "Attachment to the machine pistol;" though the graphic shows a conventional weapon. Replaced by fists in the final game.
Pistol.
Shotgun.
Machine Gun. Replaced by chaingun in the final game.
Missile Launcher.
Dark Claw. "Demon weapon that casts a dark cloud of tortured essence. Silent but deadly." Replaced by plasma gun in the final game.
Probjectile (sic). "Gives readout on enemy." Not in the final game.
Spray Rifle. Not in the final game.
BFG 2704. Changed to "BFG9000" in the final game.
Unmaker. "Demon-tech weapon that hurts pure demons a lot, demon-humans very little, tech demons some. Made of demon bones." Not in the final game.

Left: Bar-type percentage readouts.

Three readouts are shown: Health ("H," red), Armour ("A," green), and Shield ("S," blue). The Doom Bible contains descriptions of a "Beam Shield," "Disruptor Shield," "Deflector Shield," "Ban Shield," and "Shockshield;" all of which were pick-up items conferring various protections. None of these survived to the final game; the closest descendent being the invulnerability sphere.

Bottom left: Chat window.

"Chen" is Lorelei Chen, one of four intended playable characters spelled out in the Doom Bible. Again, none survived to the final game: As part of the simplification of content in later development, named characters were dropped in favour of the anonymous "Doomguy" in single-player mode and "Green," "Indigo," "Brown," and "Red" in multi-player games.

Bottom right: Keys.

Yes: The "Captain's Hand" ("Colonel's Hand" in the Doom Bible), "Sandwich," and "Heart of Lothar" were just fancy names for keys. John Romero said so himself.

Right: Weapon and ammunition inventory.

As if the interface didn't already throw too much information about weaponry at the player! All nine weapons from the Doom Bible (barring the knife) are listed with abbreviated names in ascending order of power, with the current selection highlighted. Ammunition tallies are provided for each weapon, with the arrangement suggesting that Id was considering giving each weapon its own proprietary ammunition type.

Upper right: Automap.

The illustration is a mock-up that doesn't represent any actual released Doom map...but that didn't stop me from defictionalizing it in the Doom Museum 30 years later.

Surprisingly, two pieces of player information that the earliest Doom status bar doesn't provide are a tally of lives, and a score. Both elements would make their appearance in later development, before being excised from the game entirely.

Later development

Games can change quickly while they're under development, and Doom was no exception. Literally one hour after the "0.2" tech demo was compiled, Id captured a set of screenshots for release demonstrating Doom and test levels in internal development. These were dated 1993-02-04 and 1993-02-15, and depicted a mythical Doom "0.25." The status bar had the following developments:

The four-sided surround has a simpler overlay over the playable window, removing the upper curvature and rounded corners seen in the tech demo. This was presumably done both to simplify rendering, and make it easier to render the surround as a composite of graphics rather than a single image.
The weapon display and automap in the upper corners have been made slightly smaller.
The UAAF logo has been deleted from the weapon display.
The "Shield" bar is now a darker shade of blue.
The textures in the left, right, and lower periphery have all been changed slightly.
Significantly, the chat window has been replaced in the mock-up by a graph and an array of statistics. These feature abbreviations such as "AEC" for Active Enemy Count, "TSC" for Total Enemy Count, "ASC" for Active Sprite Count, and "AN" for Area Number...some of which seems like information more suitable for a debugger than a player.
The key names are now preceded by bullets.

A third set of Doom screenshots was compiled on 1993-02-28, followed by a fourth dated 1993-03-03. For years, it was assumed that no development alphas from this period survived; however, the vintage game community was veritably rocked in 2015 when a "0.3" release (also from 1993-02-28) resurfaced after 22 years.

The automap is now functional...a phenomenal development given the early stage of development. Interestingly, the player's position is denoted by a red marker in the "0.3" alpha, but not in either screenshot set.
The player's weapon selection can now be reflected in the status bar (although it doesn't work consistently), and the ammunition tally remains a dummy number. The "MAX" and "RNG" stats have been deleted.

The weapons have been rejigged, with a bayonet-equipped rifle replacing the knife and pistol. In the right-side inventory list, "CLA" for Dark Claw has been changed to "CHA" (a typo?), and the four most powerful weapons have been deleted.
An alternate status bar has been implemented (shown below).
While not "truly" a part of the status bar, all alphas from this point on had a gauge of two-pixel dots in the lower left corner displaying the current framerate. These are visible both on the above screenshot, and on several that follow below.

Second status bar: February 1993.

Besides an operational automap, the biggest Doom development that surfaced by 1993-02-28 was a slim alternate status bar, measuring just 16 pixels tall:

This bar distills the player's readouts to the bare minimum: An ammunition tally, and percentages for Health, Armour, and Shield. None of the readouts are functional, and since the percentages leave room for only two digits, it's unclear how a value of "100%" was to have been displayed. The game tester could alternate between this view and the original helmet surround by toggling the A and S keys.

The slimmer status bar figures prominently in most of Id's later February and March screenshots, suggesting that the second bar quickly became preferred within the company and would influence Doom's subsequent UI development.

Later development

In 2015, John Romero shared a large number of assets from Doom's development with the community, including sprite sheets of the status bar under development.

This interesting take on the second status bar rearranges the elements into a double-height 32-pixel stack, opening up potential space in the opposite corner of the screen for weapon displays and other information. A score tally has been added; Health, Armour, and Shield have reverted to initials, and each display has been expanded to three digits, allowing for on-screen values of 100%.

Although it appears on a sprite sheet bearing the filedate 1993-03-30, the graphic may have been drawn weeks earlier. By this date, Id had already moved on to a third status bar design.

Third status bar: March 1993.

A compromise between the full helmet surround and the slimline version was reached early in the spring, as Doom advanced and superfluous elements from the Doom Bible began to be cut or simplified.

The result was this: A 320 by 32 pixel status bar, doubling the height of the second status bar but carrying over its brushed stainless steel appearance. These pixel dimensions would carry forth to the finished game.

This mock-up of the bar appears on a sprite sheet dated 1993-03-30. It relies heavily on graphics to convey an array of player information:

Weapon selection and ammunition tally. The weapon profile graphics are carried over from the first interface, while the font used for the tally is carried over from the second.
Health (H), Armour (A), and Shield (S) bars, continuing the abbreviations and colour codes used in the first design.
A gradient gauge of unknown significance (possibly intended to have the same purpose as the graph in later versions of the first status bar), and what appears to be a radar screen replacing the on-screen automap.
An inventory of keys, which have already started to transition away from the esoteric names of the Tech Demo and Doom Bible. Three tiles for prosaic metallic keycards appear (coloured gold, silver, and bronze), alongside what I can only assume are the Captain's Hand and Heart of Lothar.

For multiplayer chat, the right side of the status bar was intended to be replaced with a frame marked "COM," for Communication. This mock-up also reveals that Doom was still intended at this point to feature named characters, and "Chen," "Paramo," "Barrett," and "Petro" (Pietrovich) are all carried forth from their profiles in the Doom Bible.

The third status bar appeared in time for Doom's "0.4" alpha, compiled on 1993-04-02. Two of the panels were increased in size dimensionally from the original mock-up, and the inventory panel also had a thick grey border added. Unfortunately, no effort was spent to make the bar's readouts functional...though even for Id, this would have been a tall order to pull off in two days!

Fourth status bar: May 1993.

Six weeks in, the status bar was revised again. Although the design remained broadly similar to what it was before, it was changed to display more verbose information:

This mock-up of the fourth status bar was drawn on a sprite sheet dated 1993-05-13. Changes include:

The weapon's title is now displayed on the screen, as it was on the original helmet surround.
An inventory list of bullets, shells, missiles, and energy cells is now provided. This is also a reprise of an element from the original status interface; however, ammunition types are now shared across multiple weapons instead of existing one for one.
The Health, Armour, and Shield bars have been reduced in size, and no longer bear the "H," "A," and "S" initials.
The gradient gauge and radar display have been removed.
Keys have been reduced in count to three (bidding adieu to the Captain's Hand), and are now coloured blue, brown, and green. These colours may have been tentative, and two of them would soon change again.
For the first time, Doom's status bar now incorporates a timer, tally of player lives, and score. The latter two elements are carried over from Wolfenstein 3D.

A second-mock up from the same source shows the status bar with a wide communication frame for status messages and multi-player chat.

A complete set of weapon graphics intended for the bar, dated 1993-05-17. By this point in development, the chainsaw had made its debut. The Dark Claw was still tentatively slated for inclusion, but this would be its last appearance. The Probjectile, Spray Rifle, and Unmaker were already gone.

The fourth status bar appeared in the "0.5" alpha, dated 1993-05-22. The readouts are partially functional, with a working ammunition tally, health bar, and key inventory. A new font appears in the ammunition tally, with numerals both larger and darker than those used before. Although the status bar does not contain an automap or radar display, a full-screen automap has been implemented with a hotkey trigger.

There's one notable difference between the alpha's status bar and the initial mock-up: The key colours changed again, this time to the familiar primary hues of blue, yellow, and red. Even though the keys have assumed their final colours, their corresponding sprites in the WAD are still internally designated "B" (bronze) for red, "G" (gold) for blue, and "S" (silver) for yellow.

Later development

The fourth status bar was followed by Doom's "Dark Period," a four-month bout of tumult from which no screenshots or prototypes are known. Tom Hall was also forced out of Id Software during this period, spelling the end of his creative involvement. It's doubtless that the Doom UI underwent tweaks in this timeframe...but when and how remain questions for the ages.

One of the few images that survive from this era is a partial sprite sheet with key inventory icons and shadowed digits in multiple colours (which did not survive to the final game). Several renderings of the "%" symbol are visible, indicating that this was when Id made the decision to move from graphical bar-type readouts to Wolfenstein-type numeric percentages in a quest to boil Doom down to basics.

The precise age of these graphics is unknown. The sprite sheet itself is partially overwritten by renderings of the final bar graphic, and dated 1993-10-29. As with other Doom development graphics, these were saved by John Romero and released to the community years after the fact.

Fifth status bar: October 1993.

In the fall of 1993, the dust finally began to clear on Doom and its finished UI. The status bar was redesigned into its fifth incarnation, bearing the now-iconic striated grey background and red digits familiar to players. Its first widespread appearance was in the three-level Doom Press Release Pre-Beta compiled on 1993-10-04. An assortment of screenshots were released in tandem, dated 1993-10-03 and 1993-10-05.

The fifth status bar represented a return to the ways of Wolfenstein 3D, with numeric percentage values and a representation of the player's face at centre. After all the UI experimentation of the previous year, Id had effectively come full circle. The elements were:

Ammunition tally.
Health percentage, replacing the red "H" bar.
Item tally, keeping tabs on the number of collected bonus items yielding points and player lives.
Player life tally, tucked in the corner of the central portrait.
Armour percentage, replacing the green "A" bar.
Key inventory, with new graphics in the same colours as before.
An inventory list of bullets, shells, missiles, and energy cells, carried over from the fourth design with the addition of maximum magazine size figures.

Shields had been dropped from the game by this point, and the timer and score were hidden from view by default.

The status bar in the Press Release was functional, and could take on several different forms depending on the context at hand. When status messages appeared, the right side would automatically switch over to a wide communication frame much like the one seen in mock-ups for the previous two status bars.

When the player engaged the automap, the status bar would switch to display the player's score and weapon inventory. A blank panel was provided on the right, with unknown intended purpose.

The player portrait had a tendency to draw itself over the leftmost pixels of the life tally, making the digit hard to read.

The Captain's Hand didn't survive, but Doom managed to preserve a bit of variety by fielding both card-shaped and skull-shaped keys. Strangely, though, their positions on the status bar were inconsistent: Card-type keys were arranged with blue on the top, while skull-shaped keys were arranged with blue on the bottom.

Later development

Although the Doom Press Release featured a life tally, bonus items, and score, all three features were excised from the game in development about six weeks before the final release. This blank version of the status bar appears on a sprite sheet dated 1993-10-29, and features an empty panel where the Items tally previously appeared. An identical status bar appears in video footage from November 1993...by which point the communication frame had also been dropped in favour of text messages flashed in a heads-up display above the status bar.

Here's the final Doom status bar, as it appeared to players who experienced it for the first time on 1993-12-10:

The "Item" panel that appeared in the Press Release has been replaced by an array of available weapons, designated by hotkey digits.
The player portrait now has a background of dark grey rather than pitch black, and the obsolete life tally has been removed.
The player portrait, key inventory, and keycard graphics are now one pixel narrower.
Keys are now arranged in a consistent blue-yellow-red order, regardless of whether they happen to be card-shaped or skull-shaped.
The status bar now takes on a consistent appearance in all contexts...meaning that the communication frame and "score and weapons" versions no longer appear. In spite of this, their images remain in the WAD as unused graphics in Doom versions 1.0 and 1.1.

Since this on-screen image is so iconic, it scarcely needs explanation. The inventory panel can display either card-type or skull-type keys, depending on the level, and adapts the player's portrait for the conditions at hand.

In multi-player Deathmatch games, the "Arms" panel is replaced by a tally reading "Frag." The central portrait also takes on a coloured tinge, corresponding to the character's suit colour, and this also affects co-op modes.

When Doom was developed in 1993, it used the 640x400 resolution that prevailed on DOS games of the time. On a traditional CRT monitor, this renders as a 4:3 image with vertically-elongated pixels. Microsoft Windows and LCD monitors use square pixels, which give Doom screenshots (or Doom itself, running in a window) a foreshortened appearance. To compensate for this, many modern source ports alternate rows of doubled and tripled pixels in order to preserve the game's intended proportions.