Survival horror has its roots in the Adventure genre, and even today we can see versions most standard adventure game systems in modern survival horror games. But there is one mechanic–a staple of classic adventure games–that doesn’t seem to be used for horror games: dialog trees. If you’ve ever played any time of adventure game, you’ve most likely experienced a dialog tree; a non-player character will address the protagonist and you’ll be prompted to chose from a list of canned responses. Depending on your response, the non-player character’s reaction can change, and often deft navigation of the conversation is required to progress. This sort of system has persisted in adventure games for years. Even modern adventure games like Indigo Prophecy, Shenmue, and Phoenix Wright make use of dialog trees to allow for interactive conversation. So ubiquitous is this system that it ranks up with item puzzles on the list of core adventure game mechanics.
And yet, I can’t think of a single horror game that uses dialog trees. Well, that’s not really true; there are a few minor games like Kyoufu Shinbun Heiseiban and Kamaitachi No Yoru that do employ dialog trees, but these are mostly text adventure (or almost-text-adventure) games. Many horror games require the player to make choices (such as The Suffering‘s morality system), but these choices are usually binary (yes or no questions) and, unlike classic dialog trees, do not contain multiple levels of branching choices.
So what happened? Survival horror games, for all intents and purposes, are adventure games. Item interaction has been simplified and combat typically plays a much larger role, but almost all classic adventure mechanics can be found in modern horror games. Were dialog systems left behind because they somehow work against the developer’s attempts to build tension? Or perhaps they were discarded because there just are not that many people to talk to?
I don’t really know the answer, but I suspect that it has to do with the idea that horror try to be more “cinematic” than other types of games in order to better unsettle the player. Horror games are the only modern genre that I know of that consistently use cinematography and shot composition techniques to communicate certain feelings to the player (there are examples in other genres, of course, but they are typically the exception to the rule), and most horror games omit on-screen HUDs in order to better immerse the player. It seems safe to assume that the omission of dialog trees has something to do with the horror content in scary games; it may be the case that dialog trees give the player too much decision-making power in a genre that aims to make you feel helpless and out of control. Or it might be that decision trees are pointless unless the player’s decisions appear to actually affect the situation or story, and horror games require such a high level of detailed content that branching isn’t practical.
The thing about dialog trees is that they usually go hand-in-hand with non-player characters. Furthermore, these characters usually give you multiple opportunities to talk to them, so if you fail to make the correct decisions in the dialog tree you have a way to start over again from the beginning. Horror games rarely have this type of NPC; those that do appear only have a few things to say, and are not used for conversation. So perhaps the issue is that providing NPCs that can be spoken to multiple times somehow degrades the overall horror impact of the game. If the player is really to believe that their character is trapped in some dire situation, does it really make sense for people to be standing around nonchalantly, waiting to be spoken to? Giving the player NPCs to talk to, especially when they are in the thick of a high-tension scene, could be very damaging to the oppressing feeling of isolation that most horror games strive to create.
Or, it might be that dialog trees have no place in horror games because they break up the pacing. One classic problem with dialog trees is that they cause the action to stop cold while the player makes a decision, which actively works against the smooth, movie-like feel that many horror games strive for. Pacing wasn’t much of an issue back in the 2D adventure game days because the entire game was played at the player’s pace, but for a horror game good pacing has become key to building tension. Resident Evil controls its pacing by forcing the player through a funnel of locked rooms that contain keys to other locked rooms. Silent Hill, being a more linear experience, controls pacing by creating actual architecture that dictates the player’s speed (consider the impossibly-long underground stairway into the prison section of Silent Hill 2). Other games use timers, cut scenes, and a variety of mechanics to make sure that the player moves through the game at a predictable pace so that the timing of horror elements can be dictated. Without that control, the game could lose much of its impact because the developers would be unable to sequence story events in such a way that tension is increased at a steady rate.
Whatever the reason, it seems like horror developers have consistently chosen to discard dialog trees from their game designs. These sorts of decisions are what separate horror games from the pack; the designers of these titles are actively considering which game mechanics will allow them to better communicate emotion to the player and which will be detrimental to that goal. All decisions of a good horror game design must be in service to the horror experience; without this focus the player will never become emotionally engaged and the game will fail to rise above simple mechanics and environments. By omitting dialog trees from their game designs, I think that horror game developers are striving to remove impediments to emotional engagement.