A Level Theme is a categorized style of level based on mood or design. Most of the levels in Quake can be placed into different categories based on the textures of the levels.
The vanila Level Themes, or textures found in Quake, are few in number compared to the large number created by the community. Base, Medieval, Runic, and Common are the entirety of the Level Themes used in the base game. In Base, only idBase is used in vanilla Quake. Wizard, Terracotta, and Elder World are the subtypes of Medieval used in Quake.
Depending on the custom level, there may be an attempt to fit a particular theme, or it may just use some textures without a focus on one particular style. Many of the earlier levels, for example levels created in 1996, tended to not prioritize theme and thus hold a larger number of styles. Even the vanilla game was relatively inconsistent outside of idBase, often mixing themes together to highlight areas or add variety. This means that while there is often a central theme, in actuality most Quake levels don't stick to one single style.
- Base - Areas inspired by Science Fictions, tend to be futuristic.
- Canton - The Level Theme for all Q2 levels.
- Common - The absence of a specific level theme.
- Debug - A level theme made for Texture Demo 1, intended to be used for other level themes.
- Medieval - Areas inspired by the Middle Ages, range from the red clay palaces of Terracotta to the grey/green bricks of Wizard
- Runic - Made of metal alloys and concrete, these dark dungeons rarely see the light of day.
- Undefined - Level themes with no official name.