Stealth game heroes always have the best gadgets. From Agent 47’s piano wire, to Sam Fisher’s goofy goggles, to Emily Kaldwin’s fistful of superpowers - these sneaky boys and girls are often defined by their iconic inventory items. Because the truth is: stealth games aren’t just about waiting for guards to move out the way before you sneak past. Instead, they’re about using gadgets, super powers, and abilities to tip the situation to your advantage. So welcome back to the School of Stealth - a mini-series about the design of sneaky games. For episode two, we’re now deep behind enemy lines, and ready to move on. So it’s time to reach into our utility belt and pick out the five types of stealth game gadget. So, like I said, most stealth mechanics can be bundled into five key categories. Category one covers gadgets that let you gather information. Anything that lets you see beyond the limited viewpoint of your character. So while a shut door would usually restrict your knowledge of what’s behind it, Sam Fisher can slip an optic fibre camera underneath and spy on the room ahead. There’s also the motion tracker in Alien Isolation. Peeking through keyholes in Invisible Inc. Leaning around cover in Dishonored. And night vision goggles that highlight enemies in the dark. You could even count Snake’s interrogation skills, which force enemies to give up intel on guard patrols and ammo caches. These gadgets give you an informational advantage over the enemy. And as Gunpoint creator Tom Francis says “when you know more about the enemy than they know about you, you can factor them into your thinking. [And that] information is the raw material plans are made of”. These gadgets also dictate the pace of the game. The rhythm of a stealth game is defined by a moment of carefully observing the next room - and then moving through it. It’s a constant, repeating loop of observation and execution. Category two covers gadgets that let you manipulate enemies. On the previous episode, I talked about how stealth game guards can see and hear the player by using simulated eyes and ears. These gadgets let us use those sensory systems to our advantage. So the Playboy magazine, the decoy, and the dropped weapon can pique a guard’s visual interest. The sonic Batarang, the speaker on the sticky camera, and the trusty ol’ rock, meanwhile, can trigger a guard’s hearing response. Sometimes, the distracting element is actually found within the world itself, like overflowing a sink in Hitman. All of these allow us to move AI characters off of their patrol path, and into a position that works for us. For some, that might have you open a tiny window in the guard’s patrol so you can slip past unnoticed. For others, it’s about luring enemies into traps or guiding them into the dark for an easy takedown. You can also go further and use gadgets to change the guard’s behaviour. In Mark of the Ninja, the Terror Dart causes an enemy to become panicked and paranoid, and you can use this to make them accidentally kill their own team mates. Category three covers gadgets that let you redefine space. And to make sense of them, we need to take a moment to consider how stealth game levels are designed. Thief’s project lead Greg LoPiccolo talks about “space being the commodity that you are trading in”, and points out how a stealth game level is split between areas of safety and danger. In Thief, that idea operates on two axes: light and shadow on one axis, and loud and quiet on the other. Other games might have a different split, like high and low in Batman or public and private in Hitman, but the idea is the same: a stealth game level is like a sea of danger, and you’ve got to swim between the islands of safety. However, these gadgets let you manipulate this set-up. So in Thief, the water arrows can douse candles - turning a brightly-lit area of danger into a dark corner of safety. On the other axis, the moss arrows can create grassy rugs that you can stand on without making noise, changing that zone from loud to quiet. Another twist on this, is letting you change your character so that you can exist in a dangerous space, but with relative safety - like using the camouflage system to blend in with the surroundings in Metal Gear Solid 3, or using disguises to upgrade Agent 47’s credentials in the Hitman series. These gadgets let you see levels as not just a static puzzle to solve, but an opportunity to change things so they put you at an advantage. Category four covers gadgets that let you alter your movement. Typically, these are mechanics that let you reach spots that guards can’t get to. So, there’s Batman’s grapnel which lets you shoot up to the gargoyles that are high above the room. Sam Fisher’s split jump, which - in certain corridors - lets you stand above enemies without being seen. And there’s Dishonored’s wonderful short-range teleport move: Blink, which lets you clamber up to high up places - and also dart between areas of cover. We don’t see these audacious moves in every stealth game, though. Mostly, these games concentrate on stances - like standing up, crouching down, and laying prone - all of which confer different levels of visibility, noise, and speed of movement. Finally, category five covers gadgets that let you incapacitate enemies. Where would stealth games be without the blackjack, the trip-mine, or the trusty (and admittedly unrealistic) silenced pistol? The stealth game fantasy doesn’t preclude taking out guards as long as you cover up the evidence. Importantly, though, stealth games don’t often give you machine guns and rocket launchers. Because, if you think about these five types of gadget - they’re about letting you find an advantage over the enemy on practically every axis - except sheer brute force. You know more, you can move more freely, and you can manipulate guards into doing what you want - all of which puts you in total control, until you get into a straight up firefight. But more on that in a future episode. The other thing that these gadgets all have in common, though, is that they must be balanced. Without careful consideration for how these mechanics should be limited or countered - they can cause all sorts of problems in the design. So, unrestricted use of gadgets that let you manipulate enemies and space can lead to dominant strategies - which are simple and incredibly effective tactics that you can use again and again, in place of more interesting solutions. Things like using an endless supply of rocks to slip past braindead enemies, or dousing every torch you see. Gadgets that confer too much information can break the flow of the game. So in Assassin’s Creed Origins, you can fly your eagle buddy over a base like a feathered drone, and tag every enemy you see. This then gives you complete knowledge of where that enemy is, for as long as they’re alive. This breaks that wonderful stealth game rhythm, essentially flattening it out into a single, effortless observation stage - followed by an unimpeded, and relatively low-stakes, execution phase. And using overpowered weapons to kill (or permanently incapacitate) every guard you see can actually reduce the complexity of the situation. Game design professor Robert Yang says that killing foes in stealth games “depopulates a level, severs connections between systems, and makes the game boring”. If you’ve ever had to exfiltrate a Dishonored level by simply walking past all the corpses you made earlier, you’ll get what he means. Oh, and there’s also that problem of x-ray vision modes being so helpful that you never want to turn them off - making the entire game look like it’s being played on an airport security monitor. So how can we balance the power of these gadgets? One way is to give systems inherent limitations. Look at Ghost Recon Wildlands, which has a very similar system to the eagle in Assassin’s Creed, but the bird is replaced with a UAV that has a limited battery, a short range, and can be shot down by observant enemies. It lets you gather information, but it’s not omnipotent. Likewise, The Last Us does let you see enemies through walls - but only when the enemy is making noise. And Deus Ex lets you tag enemies, but there’s a limit to how many you can track simultaneously. Another way is to make your power temporary. Sam Fisher can overflow fuses to turn off lights, but they’ll soon flicker back on. A smoke bomb creates a tiny and temporary pocket of safety within a danger zone. And when you knock out enemies in Invisible Inc, they’ll wake back up after a few turns - unless you sacrifice one of your team mates to pin them down. A rather obvious way to restrict something’s power is just to limit how many you have. In Chaos Theory, you only get a few sticky cameras per level, and in Thief you have to pay for water arrows with the money you stole in previous stages. While some games let you throw infinite stones with a touch of the button, Dishonored makes you find physical objects in the world. And in Hitman, you can only stuff two enemies in a cupboard before it’s full up. You can also give AI the ability to counter your best moves. Enforcers in Hitman are characters who can see through disguises, so private areas keep some of their danger. And in Shadow Tactics: Blades of the Shogun, enemies who wear straw hats simply aren’t distracted by rocks. I don’t know the logic behind that decision. But, hey, video games. This can also be handled adaptively, like in Metal Gear Solid V where guards will start wearing helmets if you’re too handy with the headshot. An even bolder take on this idea is the game ECHO, where enemies learn and then copy your tactics, which means if you stick to one powerful technique, you shouldn’t be surprised if your opponents start using it against you. There’s also an opportunity to provide unique set-ups for certain levels or areas, which temporarily thwart your favourite plans. In Splinter Cell: Chaos Theory, for example, there’s a level on a ship where the engine room is filled with gas - which means you can’t use your weapons or everything will go boom. Then there’s the layout of the level and the guard patrol patterns. One guard on their own can be easily dispatched, but two guards who are looking at each other will require a much more complex plan to overcome. And, finally, there are abstract systems that exist outside of the current situation. So killing a guard in Invisible Inc causes the alarm system to ratchet up one level, and using lethal takedowns in the Dishonored games makes you miss out on certain grades on the end-of-level score system, and can cause changes in the narrative. The idea is to make players more thoughtful about the tactics they use, and try to stop the game from veering into a more simplistic experience. So using weapons should be risky, not effortless. Information should be carefully gathered and imperfect, not handed to you. And strategies should be mixed up, not endlessly repeated. That’s it for lesson two. Come back next time for more deep dives into sneak ‘em up design. For now, let me know your favourite stealth game mechanic in the comments down below. Hey. Thanks for watching! GMTK recently hit 800,000 subscribers here on YouTube, which is just amazing. If you hit the bell icon next to the subscribe button, you will also get a notification your phone when I release a new episode. 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