Cell Block 4 - Cell Block 4, where the player starts both versions of the map. The heavy shadows to the sides allow the player to familiarize themselves with the stealth versions mechanics in a relatively low risk area.

Description: Duality is my Half-Life 2-based level/minimod from my Masters Thesis project at the Guildhall, entitled “The Effects of Adding Stealth Gameplay to the Level Building Process of an Action Game.” The title of the project sums up what the thesis was actually studying; I wanted to see what would happen if I approached the design process with the intention of the created level being used for both straight up action gameplay and stealth gameplay. Half-Life 2, however, is not a game that supports any sort of stealth gameplay out of the box, so I knew from the start that it would require, at the very least, an extensive amount of scripting, if not outright source code changes.

Duality is essentially a mini-mod that includes two versions of the same level layout, one stealth-focused, and one action-focused. While the action-focused version is closer to a traditional Half-Life 2 single-player map, it still includes some of the basic stealth functionality included in the stealth version. 90% of the changes made to create a believable stealth gameplay experience were through the use of extensive level scripting; the other 10% were very basic code changes that modified some existing behavior of the AI guards. A break-down of the scripting setup used can be found ›› here ‹‹

While these scripting changes allowed me to create somewhat believable stealth gameplay inHalf-Life 2, the final implementation was flawed; the Half-Life 2 AI was simply not designed with stealth gameplay in mind. While I had initially planned to try and make some code changes to the base AI, the Source Engine AI code was simply too difficult to break into with my limited time frame and LD-with-some-programming-background skill set. Even so, the end result of the study was that players in the focus study group enjoyed both versions of the level, even with the somewhat flawed stealth implementation.

Creation Time: 10 Weeks
Assets Created: BSP/Mesh Placement, Screen Overlays, Stealth gameplay script, minor code modifications (swapped crowbar for stun baton, AI view cone tweaks, overlay association with new trigger volumes)
Requirements: Half-Life 2: Episode Two
Documentation: Download Final Draft of Thesis (.doc, 7.8 MB)
Download Final Draft of Thesis (.pdf, 30 MB)
Download Prison Break (action version of map) Level Design Doc (.doc, 9.5 MB)
Downloads: Download Duality Installer (.exe, 13 MB)