Despite being a relatively short prologue to Metal Gear Solid V: The Phantom Pain, Metal Gear Solid V: Ground Zeroes is an important milestone for the stealth genre. It is building on a relatively recent trend running through other stealth icons: a renewed focus on failure design. In other words, Ground Zeroes has figured out how to make failure fun, by giving you the scope to turn each little failure into an opportunity.

Failure as a gameplay state is far more commonly encountered in the stealth genre than in more popular genres like shooters and role-playing games. Perhaps because of this, the stealth genre has struggled to crawl out of its cubbyhole and find mass appeal. Stealth games require patience and dedication, are often brimming with complex concealment mechanics and deep enemy artificial intelligence, and withhold their payoffs to maximise long stretches of tense gameplay. These factors can make stealth games appear initially intimidating, but with time they become the reason the genre can be immensely captivating.

One of the most egregious factors that was turning people off stealth games was the frustration brought about by total failure. Elements like forced game-over screens upon being detected and clunky controls surrounding the last-ditch use of less-stealthy weapons felt like artificial difficulty increases that simply resulted in the reload of a save game.

A stealth game that exhibits good failure design is one that is less abusive to you.

Understandably, not everyone finds this stop-and-start gameplay fun. So recent stealth games like Splinter Cell Blacklist, Hitman: Absolution, and Ground Zeroes exhibit a renewed focus on failure design. Extra attention has been paid to the gradual failure states of these stealth games, and to what options are open to you once you trigger such a failure. A stealth game that exhibits good failure design is one that is less abusive to you, by replacing its hard game-over screens, or reasons to simply quick-load, with mechanics that extend or alter gameplay beyond failure in interesting and engaging ways.

The gameplay within those failure states needs to be tense, thrilling, and fun--all the things that moving undetected is, as well. Supporting an action approach is the first step. Combat controls need to be responsive. Weapon feedback needs to be punchy. Enemies need to behave in a manner that makes them challenging combat opponents, but one that also provides you with opportunities to slip away and reset your detection state.

But if an action approach is well supported, what stops you from taking this path of least resistance when a stealth approach still requires the same patience and dedication as in the earlier games in the genre? If good failure design turns stealth games into stealth-action hybrids, why should you sneak when shooting can be just as fun? Ground Zeroes answers this by pursuing an approach to failure design that gives you the information and ability to turn failures into opportunities.

Ground Zeroes is billed as one of the first open-world stealth games. Stealth gameplay and open worlds have met before in the likes of Far Cry 3 and Assassin's Creed. But those games contained their stealth encounters to distinct pockets within their open worlds by way of mission area boundaries. In Ground Zeroes, the whole environment is enemy territory. Nowhere is safe. That's standard operating procedure for Snake. But the sheer scope of Ground Zeroes' open-world approach creates a vast playpen of interconnected systems that exist to nudge you closer to, or further from, failure.

Reacting to this push-and-pull as you navigate Camp Omega in pursuit of your objectives keeps tension high, because this larger physical environment is accompanied by an increased consequence for significant failure. Getting spotted, or creating a loud enough disturbance, completely disrupts the behaviour of enemies not just in your immediate area, but throughout the entire location. In stealth games without the scope of Ground Zeroes' open world, this would usually result in just a few minutes of tense, reactive gameplay as you attempted to creep past twitchy trigger fingers before the situation reset, or before you made it to a new safe area. In Ground Zeroes, those few minutes could potentially become an hour or more. The sense that you are infiltrating a large location is all the more real when that location exists without load screens, and the consequences for disrupting that system are felt across its entirety.

The sense that you are infiltrating a large location is all the more real when that location exists without load screens.

This greater consequence to failure within the scope of an open world would make for frustrating or overwhelming gameplay if not for the fact that such disruption creates opportunities. Part of this involves the removal of the radar to make way for Ground Zeroes' spotting system, whereby guards can be tagged with markers to remain visible through walls. The more time you spend creeping around the base and utilising multiple vantage points to spot enemies, the more information you will have when guards become alerted.

At an initial alert phase, the game won't spawn new guards from off the map, so you're dealing with a consistent threat level. In this respect, the failure of alerting enemies or making them suspicious becomes fun, because the work you put into marking those enemies allows you to poke and prod at the AI with intent. Want to get through a heavily guarded area? Plant some C4 explosives on the other side of the base, sneak back to the guarded area, detonate the bomb, and watch the markers above all the enemies you've spotted show the guards leaving their posts to investigate--giving you the opportunity to slip by. Sure, alerting enemies at all is a small failure in a stealth game, but the fact that this plays out on the scale of Ground Zeroes' open world makes the sensation that you are exploiting an opportunity all the more tangible.

The situational awareness acquired through spotting enemies, and the opportunities that awareness can be exploited to create, does not come at the cost of tension. Keeping you tense by balancing you on the knife's edge of chaos and control is what stealth games do best. But tipping too rapidly into chaos replaces tension with frustration; the best stealth games instil a sense that control is gradually being wrested from you. It's the idea of building in smaller, analogue failure states that stack upon one another, as opposed to one of two binary states: being hidden, and every guard knowing exactly where you are.

If you're executing this master plan, but a single guard catches a glimpse of you as he runs to investigate the explosion, what then? Ground Zeroes' new reflex system accounts for the first slip off the knife to create its own small and self-contained failure state. When you're spotted by an individual guard, the game will go into slow motion and allow you to lock on to that enemy's torso with your currently equipped weapon. You then have just a few seconds to take that guard down before he radios in and initiates a camp-wide alert. This reflex system strikes a fine balance between accessibility and consequence. You still need to manually aim for the head for a clean takedown. You don't have time to change weapons, so you're committed to firing with whatever is currently equipped--let's hope it's silenced. And the very real consequence of a dead body is something you will still have to deal with, quickly. It is a fantastic piece of failure design; it augments Ground Zeroes' polished action controls but still requires skill, precision, and the ability to account for the consequences.

What makes Ground Zeroes so fascinating is how those consequences can filter out like a butterfly effect. Let's say you take this guard out in reflex mode and move his body. Another guard may be driving a truck from the other side of the map past that body, and he'll pull over to investigate. That truck may be your way to progress even deeper into Camp Omega by hiding in its cargo tray. Can you take out the driver before he radios for backup? How will you get further into the base if the driver is dead? Can you risk driving the truck yourself past the remaining guards?

In Ground Zeroes, tension remains high as small failures can potentially snowball into something worse. But even as that snowball picks up speed, you always have the chance to change its course and turn those failures into opportunities. The scope of the game's open world and the systems within it allow for such a wider range of smaller failure states that each little mistake is perfectly readable and sufficiently tense.

Ground Zeroes' new spotting mechanic promotes a risk versus reward play style, while the world is filled with elements that promote creative problem solving. That the game does all of this without compromising your ability to pursue a perfect stealth approach if you desire is a significant landmark for the genre.

But as good as Ground Zeroes is at making failure fun, the playpen that is Camp Omega eventually becomes too familiar. If the game's mechanics translate well to the far more massive open world of The Phantom Pain, then it's possible Kojima Productions may be in the midst of creating one of the most important stealth games ever made.