It’s not uncommon for games with a well defined core mechanic, specifically action games, to include sections with different mechanics to break up the pacing and provide variety. When it comes to these “palette cleanser” sections it seems the stealth section is on a par with the turret section as the favourite choice of developers. If a new action game doesn’t feature one it will almost certainly feature the other, if not both. With very few exceptions stealth sections in games that haven’t been designed specifically around stealth mechanics are poorly executed. Think of any recent game with a stealth section; it was likely passable at best, if not outright unpleasant.
The obvious argument is that simple resource management means any mechanic used only for a single section of a game is going to receive less attention than a mechanic around which the game is focused. I’m sure this is true and has an affect on the implementation of stealth sections, however I believe there is a specific problem with the mechanics of such sections; they are based not simply on poorly implemented stealth mechanics, but on bad stealth mechanics.
Stealth games are about power and the relationship of power to physical location. Good stealth games make the player a powerful agent in a world designed for them to exercise that power, bad stealth games make the player a weak agent in a world designed to reinforce that weakness. Bad stealth games, and by extension bad stealth sections, confuse being stealthy with hiding. It’s a fine distinction but an important one.
Consider Garrett, protagonist of the Thief series. Outside his cynicism his defining attribute is that he becomes invisible when in a dark area. It might never be explicitly stated but when the Light Gem is completely black Garrett is, for all intents and purposes, invisible. Darkness is a safe zone for Garrett and he has a variety of tools at his disposal with which he can alter the environment to increase the size of that safe zone.
This basic concept, the manipulation of the environment in your favour, is also present in the Splinter Cell series. Sam Fisher shares Garrett’s curious ability to become invisible in the dark, but the nature of the darkness as safe zone is taken further by the inclusion of alternative vision modes that allow him to see as well in darkness as light.
Both Garrett and Sam Fisher operate in environments which are, the majority of the time, in darkness. Environments where they are the ones in positions of power. The various guards and other non-player characters in the world might be better armed and more numerous than either protagonist but they lack a lot of their abilities. To them the darkness is a hindrance, to Garrett and Sam Fisher it is home. With access to an enhanced move set and the ability to modify the world around you, playing as either protagonist you have the upper hand. You have the ability to plan your approach and the moment at which you act. Things don’t always go as planned and you often have to improvise to survive but the choice of where and when to initiate action is yours.
Compare this mentality to that manner in which stealth sections in action games are presented. The core mechanics of such games provide the player with the most power when they are heavily armed and operating in open well lit environments. The available verbs are those that make the most of that environment. When such games enter a stealth section the rules are changed, the previously available verbs, are either entirely removed or drastically curtailed. Non-player characters are now the ones operating from the position of power. Darkness for Garrett provides the ability for concealed movement and safety, for the standard action game protagonist it represents a diminished vocabulary and restricted move set.
This use of a diminished vocabulary in order to encourage stealth gameplay can be seen clearly in the two stealth sections of Fahrenheit (aka Indigo Prophecy). Both sections are a variation on the same theme, with the teenage Lucas trying to gain access to a restricted hanger on the airbase on which he lives. Stripped of the ability to interact with anything beyond that which is required for forward progression there is no choice of where and when to initiate action, the player must react to the game world and respond correctly or fail and be forced to restart the section.
Good stealth mechanics revolve around making the player powerful and giving them the means by which to exercise that power; bad stealth mechanics revolve around making the player weak and requiring them to work to mitigate that weakness.