Halo Wars 3 (rejected pitch)

A rejected pitch for Halo Wars 3 was unveiled in 2017 through concept art.

Background
In 2017, Creative Assembly artist Brad Wright released concept art based on the pitch, alongside concept art for a cancelled pitch for Halo Wars 2: Awakening the Nightmare that was to feature Promethean enemies. He received permission to release the art on his ArtStation page from Microsoft. Space battles would feature in the game, with a capital ship serving as the home base, from which ground forces would be deployed. Different rooms on the ship would provide bonuses, some buffing the ship itself in ship-to-ship battles. Buffs would affect elements such as shields and thrusters.

The ArtStation page's description was later removed, replaced with "Halo Wars 2 additional work done for Creative Assembly for Halo Wars 2. Property of Microsoft." Wright provided no explanation as to why the change was made.

In 2020, concept artist Bill Yi uploaded some concept art to ArtStation and his personal website with filenames, depicting more space battle content and some ground battles. These concepts can be viewed below.

As of February 2021, 343 Industries still had no plans to produce another game in the Halo Wars series.

Trivia
The artwork produced heavily featured the UNSC Frontend, a stand-in ship for the ship that would be featured in gameplay and named after the user interface being the "front end" of a game. The ship is classed as an "M-class carrier" and has a registry of "18384973-YU". The ship was constructed in the "Outer Sol Docks" and was captained by "Captain Steve". Visually the ship is a mix of the and the fan-made "Nevada-class heavy frigate", with the addition of "wings" reminiscent of those on the. Another concept piece labels the year as 2567, adding that the ship is in "Low Ark Orbit" and at Alpha Centauri.