Stealth games have always filled a different role in the gaming world. Instead of being an invincible badass that can mow down hundreds and hundreds of enemies, the player is weak and must use their brains to prevail instead of their brawn. Over the years the stealth genre has grown and become more complex. Other genres have even borrowed stealth elements. However, some studios took the idea to use stealth elements but never learned how to do stealth, so here is what makes good stealth games.
The first thing that makes a good stealth game is arguably the most important, detection. If the detection isn't clear and consistent then the player can't plan around it and be detected will feel like the game cheating instead of the player screwing up. An example of bad detection is Styx: Master of Shadows.
In Styx, the player is able to use the shadows to conceal themselves. However, whether or not a guard will see you is, at best. a crap shoot. Some enemies can see through shadows and some can't, and the only way to find out is through trial and error. Another thing that is necessary for a good stealth game in regards to detection is when the enemy calls for reinforcements.
If the enemy immediately opens fire upon detection, it will feel more like aimbot instead of being found by the enemy. This is an area Styx does well. When the player is detected the enemy recoils slightly and calls out to his friends before he attacks. This gives the player options. They could go for the assassin option and try to kill the guard before he tells his friends or they could get a head start on finding a hiding place.
Another thing that makes for a good stealth game is what happens when you get detected. Many games make the player run and hide for a while till the guards stop looking. This makes sense since that is what a lot of people would do. However, from a gameplay view, this isn't great. Forcing the player to sit in a location waiting for the guards to lose them just so they can try what they were doing again is not a great idea. The forced stealth sections of the Assassin's Creed games sometimes do this.
Sitting in a hay bale while waiting for the guards to go away is not fun. This means Stealth games need to do something contrary to the rest of the gaming world, they need dumber AI. Well... that's not exactly right but it could be a solution. Stealth games need their AI to continue the process a human would when finding an intruder.
Humans, after finding an intruder and losing them, will either search for that person in the immediate area or to secure other means of entry. Putting that into game terms means that after getting to the last place the player was seen, the AI will need to have some of the pursuers look in the areas around where the player was last seen. The AI will also need some of the guards to look at other entryways for this to be believable.
The final major thing stealth games need is to have failures be recoverable. What does that mean? It means that if the player screws up, they have a way to recover the situation without needing to fully retreat or reload a save. I'm going to use Metro: Last Light as an example here. Say the player rounds the corner and is confronted by two guards that haven't seen him yet.
The player has options to keep him hidden. They could throw knives at the guards, use silenced weaponry, they could use their pneumatic rifle to silently kill them, or, if the lighting allowed, be quick and go back around the corner and let luck determine their fate. The point is there are a lot of ways in that situation to keep the alarm from being raised. Something that makes this hard to achieve is what I like to call, Hive Mind Syndrome.
We've all seen cases of Hive Mind Syndrome. You accidentally let one guard see you and now every guard in the whole complex knows exactly where you are. Hive Mind Syndrome can be very annoying and result in a player putting the game down out of rage instead of satisfaction
Those are the things that make a good stealth game. Clear and consistent detection so that the player can adequately plan around guards, AI that doesn't punish a player by making them wait forever, and systems that make minor mistakes not mean complete failure are all crucial to making a good stealth game. Hope you enjoyed