Cut Halo: Combat Evolved levels

"[Crunch] happened on Halo 1 as well, of the 25 planned missions for Halo, we shipped 10. Part of the problem is that as team size grows, all the really informal, seat-of-your-pants stuff you've been doing just doesn't work."

- Chris Butcher on Halo's cut levels.

During the development of Halo: Combat Evolved, the game took many forms including real-time strategy, third-person shooter and eventually, first-person shooter. As the game transitioned into an FPS and a release for the Xbox platform, work on the game's campaign still hadn't begun by September 2000. Mission brainstorming later began in earnest in December with the rest completed over the course of 2001. This page documents the levels known to be cut from release, predominantly those planned out for the game's final FPS release.

Overview
"I vividly remember building, literally on 3x5 index cards, a number and letter system. A10, A20, A30 and so on for each one of the missions. B30 was “The Silent Cartographer”. I pinned them to a board and I just stared at it for hours. There must’ve been 40 of those cards of there, and I’m like: “There’s no way in hell we’re going to build all of this.”"

- Marcus Lehto on Halo's cut levels.

When planning out Halo: Combat Evolved's campaign, Marcus Lehto originally planned things out on 3x5 index cards, with a number and letter system assigned. These names can be found in the final game map files, and are listed as such below;
 * A10 - The Pillar of Autumn
 * A30 - Halo
 * A50 - The Truth and Reconciliation
 * B30 - The Silent Cartographer
 * B40 - Assault on the Control Room
 * C10 - 343 Guilty Spark
 * C20 - The Library
 * C40 - Two Betrayals
 * D20 - Keyes
 * D40 - The Maw

As can be seen in the numbering, there are several missing gaps indicating where levels were to be included, before being cut. At some point in development, the 40 missions Lehto planned out were eventually reduced to a more manageable 25, though another 15 were later cut for final release.

Alpha Base
The series of storyboards marked X40 depict a cutscene not featured in the final release of Combat Evolved, set after the end of the level The Truth and Reconciliation. The cutscenes depict the commandeered Spirit dropship (notably shown flying backwards due to a mistake on Wilson's part) returning to Alpha Base, flanked by Longsword fighters. The Spirit lands on the base's landing pad to an audience of hundreds of assembled Marines, who cheer at the return of the Captain and the Master Chief. The crowd is hushed and Keyes gives a speech, before turning away from the crowd and addressing the Master Chief and Cortana directly.

This mission lines up with a cut level recalled by Joseph Staten during the Halo: Combat Evolved developer commentary included in the Halo 3 Legendary Edition, in which he mentions that a level was intended to take place between The Truth and Reconciliation and the following mission The Silent Cartographer, which would have explained the purpose of Installation 04 and its purpose as a weapon. This mission was ultimately cut and the information relegated to the cutscene on The Truth and Reconciliation in which Keyes is saved from the brig; a decision later mocked by the developers who referred to the Captain as "Captain Exposition". It is likely that the cutscene shown here would have served the purpose mentioned by Staten.

These storyboards also give a look at what Bungie intended for Alpha Base, later featured heavily in 2003's Halo: The Flood as the UNSC base of operations on the ring. Part of the original pitch of Halo: Combat Evolved would have seen the player waging a larger guerilla war against the Covenant on the ring, though by the final release almost all mentions of a UNSC home base on the ring were removed for time. The base in these storyboards resembles a beam emitter like those featured elsewhere in the game, though the base as visualised in 2018's Halo: Fireteam Raven has a drastically different appearance.
 * X40 1

Level after The Silent Cartographer
In early drafts of Combat Evolved, a level was intended to take place inbetween The Silent Cartographer and Assault on the Control Room. This level was ultimately cut for time, and the cinematic depicting Echo 419's descent inside the bowels of Installation 04 was included instead to justify the travel to a completely new region in the next level. A lack of resources at the time meant no matte paintings were available to depict the dropship flying above-ground.

Despite this level being cut, The Silent Cartographer and Assault on the Control Room retain subsequent ordering of B30 and B40 in the files, respectively - indicating that one of these missions may have been renamed in the course of development, or started development after this level was cut.

Volcano level
One level discussed for development around December 2000 involved "volcanos and heavy machinery". Little is known aside from this.