Why Stealth Features Make Not A Stealth Game

After a lukewarm reception to Assassin’s Creed III following its release that some fear may have disillusioned some fans, Ubisoft went all-out in their marketing campaign for Assassin’s Creed IV: Black Flag, the latest in the series. As a fan of the series (and, incidentally, one who didn’t buy AC3 following the less than perfect feedback it got), I have no problem with this, and was intrigued and excited to see some of the features being implemented get put to use. However, one particular bit of promo material that caught my eye was the stealth gameplay walkthrough, which talks up the various stealth features employed in the game.

[Yes I am perfectly aware that this post is hideously out of date- I’m working through a backlog here]

Y’see, watching that video got me thinking about the role of stealth in the Assassin’s Creed games, and eventually led me to the conclusion that, at its heart, the Assassin’s Creed series is not a stealth franchise. I could justify that statement by pointing out the huge variety of stuff the game offers beyond stealth (free-running, the admittedly awkward ‘wait around for counter chances’ combat, and traversing the high seas spring instantly to mind), or by pointing out the extent Ubisoft is prepared to go to to ensure you don’t ever actually have to use stealth if you don’t want to- I mean for heaven’s sake, they’ve just announced a new mobile game based on Black Flag called Assassin’s Creed Pirates, which allows you to do all the sailing around and piratey things without any of the exciting running around on rooftops that made the game so popular in the first place. But this wouldn’t actually address the core reason behind the AC franchise’s non-stealthness- for that we must consider exactly where the stealth genre comes from.

To explain: every game genre is basically defined by a single, core game concept, a sort of combination of mechanics and the emotional hooks that get us to enjoy (or not, as the case may be) games of that genre. In an RPG it’s about the characters and your advancing skills, in a strategy game it’s about the concept of ‘playing god’ and dictating how a whole system works rather than an individual, and in a stealth game the core concept involves hiding. This central concept naturally extrapolates itself into a series of other features after a while. In many (but not necessarily all) cases, waiting becomes a core mechanic too, as once our protagonist has hidden from whichever bad guy is appropriate it would be strange for him to be able to move out of cover immediately- as Extra Credits said during their episode on the subject of stealth, the trick to making a good stealth game is to make waiting fun. Not only that, but a key part of making the experience of hiding compelling and fun is for the player to be able to use it aggressively to their advantage. Thus, protagonists in stealth games are also generally able to make highly effective sneak attacks on an unaware enemy, frequently one hit kills such as slitting the throat or the Dishonored choke hold.

Thus far, Assassin’s Creed is sounding very like a stealth game, and it’s true the games have always featured stealth gameplay heavily. The game’s most characteristic feature is, of course, the hidden blade, intended specifically for insta-killing an unaware enemy (with the option for a suitably dramatic dive throwing them to the ground for good measure), and in later games this can be adapted to allow an enemy to be poisoned, meaning he won’t die until you’re well out of reach of any blame. AC2’s introduction of attacks from ledges, hide spots and rooftops also expanded on this, introducing a new range of ways for a player to get into a killing position whilst remaining undetected. Not only does the series’ ever expanding array of hide spots help this, but they also give the option of helping a player to run away from a fight if they so choose, meaning fighting need not be the only option. But then again these features alone aren’t enough to make a stealth game: by way of example, Skyrim had a sneaking system that allowed for high-powered sneak attacks on unaware enemies, but is quite clearly an RPG with a few stealth elements rather than a true stealth game.

Thus, mere adoption of stealth gameplay features does not make Assassin’s Creed a stealth game, and it fundamentally is not one for the following reason: for hiding and waiting to become a game’s central features the player must have a reason for doing so; hiding must benefit the player in some way. Not only that, but the usually slower-paced stealth approach must some how become the more attractive option compared to a full-frontal assault, which from the start has the advantage of being faster, more direct and more exciting. One can attempt to railroad the player down this route by making the player instantly fail if they are detected (as the AC series has done on multiple occasions), but this is a clumsy way of doing things that fails to make the stealth experience more fun and only serves to frustrate the player as to why they can’t just rush in all guns blazing. In most true stealth games, the player is forced into hiding by making it the most favourable defensive tactic (ie the best way to stay alive), which is achieved by making sure they have relatively little health/armour/defensive ability so can’t really stand up in proper combat.

And this, really, is what distinguishes Assassin’s Creed as not fundamentally being a stealth game. The combat in AC games is frequently (and rightly) criticised for being formulaic and repetitive, and part of the reason behind this is that all AC characters are really good at defending. To block just about all incoming attacks merely requires the ‘high profile’ button to be held down, and if the counter button is pressed at the appropriate moment then almost every incoming enemy can be killed the moment they attack. If countering isn’t your style, then many a foe can be taken down by simply bashing the attack button, and as later games allow you to upgrade your weapons by the end this can result in a very quick death for any NPC foolish enough to get in your way. And all that’s presuming the player wants to stand and fight; even in AC1 enemies could be taken out from afar with throwing knives (which I suppose could be tenuously considered stealth weapons), and by later games our protagonist has grenades and a ****ing gun* at his disposal, which aren’t stealthy by any stretch of the imagination.

By making it so easy to fight, to cut through swathes of enemies with hardly a thought, the developers of Assassin’s Creed have ensured the focus of their game is not about stealth, and although this is by no means a bad thing (not every game need be stealthy) this fact does, I feel, somewhat undermine many of the stealth features they have chosen to include in their various games. Just so I can consider my point proven, some months ago the Assassin’s Creed Facebook page asked its readers which series was their favourite: Assassin’s Creed or Thief, the series that almost single-handedly invented the stealth genre and had recently announced a new game (the fact that this game has subsequently turned out to be terrible is, of course, an entire other point). How did these people, who I shall remind you were writing on the official Assassin’s Creed Facebook page, respond? Why, overwhelmingly in favour of Thief, of course.

This was, however, before AC4 was released.

*That list doesn’t even mention stuff like the hookblade and parachutes which, cool though they are, do nothing for the games’ stealth elements other than distract from them.

Arr, me Hearties…

Piracy has been in the news a lot recently, mainly concerning blokes in Somalia armed with AK47s running around attacking cargo ships. However, as some regular readers of this blog (if such there are) may be able to guess from the subtle hints I regularly drop in, the pirate news I have been most interested in recently concerns Assassin’s Creed, and the recent announcement of Assassin’s Creed IV: Black Flag. This is the first AAA game that I’ve ever heard of set in the ‘golden age of piracy’, and so I thought a post on this period of time might be in order. Plus, I think a 200th post deserves a cool topic.

When people think of piracy, the mental image conjured up is always of Caribbean piracy during these days; swashbuckling men in fancy hats & coats, swanning around in large ships with flintlock pistols, cannons and oversized cojones. Captain Jack Sparrow, basically. Specifically, they refer to the situation in and around the Caribbean from around 1650 to the early 1800s, peaking during the first 30 years of the 18th century. These were the days of colonial wars in this area; 200 years earlier the Spanish-sponsored Christopher Columbus had discovered the New World and Spain, which was at the time the richest and most powerful nation on earth, smelt an opportunity. Newly unified into one nation after pushing out the Moors and uniting the powerful crowns of Aragon and Castile through marriage, 16th century Spain was finally able to utilise the great wealth that centuries of war had been unable to use productively, and swept across the Atlantic (and, indeed, much of the rest of the world; theirs was the first Empire upon which ‘the sun never set’) armed to the teeth. The New World offered them vast untapped resources of gold and silver (among other things) that the local tribes, had not extracted; these tribes were also lacking in gunpowder, and were totally incapable of dealing with the Spanish onslaught that followed. Even small raiding parties were able to conquer vast swathes of land, and Spain pillaged, raped and murdered its way across the land in a fashion eerily preminiscient of the ‘rush for Africa’ that would follow a few hundred years later. America was rich, it was untapped, it was (relatively, compared to, say, India) close enough to be accessible, and Spain got there first. Seemed like a great deal at the time.

However, cut to a couple of hundred years later, and Spain was in trouble. The ‘Spanish Golden Age’ was on the wane, and Spain found itself at near-constant war, either with France or from the Turkish Ottoman Empire, whose Barbary pirates (the first time piracy enters this story) would frequently trouble Spain’s coastal possessions. In the colonies, things were just as bad; Britain and France had established their own empires in North America and fought frequently, if not with each other, with Spain for its colonies in Florida and Central America, constantly attempting land grabs in and around the Caribbean area. Spain simply did not have the ability to maintain a military presence across such a vast area, especially when a succession war started and all parties started fighting over the future of Spain as a country and an empire, making the game of ‘who’s on whose side’ even more complicated. The whole area turned into one chaotic mess of sporadic fighting, where law was impossible to enforce,towns were frequentl either destroyed or changed hands, and honest trade such as farming became an unreliable source of income when your crops kept getting burnt. However, at the same time, there were still lots of goodies being sent around all over the place for trade purposes so the various  countries involved in the conflict could make some money out of the whole mess, wherever possible. So, let’s have a sit rep; we have large amounts of very valuable goods being shipped all over the Caribbean & the high seas, frequently alone since all powers had so few ships to spare for escorts, nobody is able to reliably enforce the law and we have a lot of men unable to make a living from practicing an honest trade. Rocking up in a large ship and stealing everything has never seemed such a productive strategy, particularly when some towns turned lawless and became pirate ports.

Interestingly, all the colonial powers at one time or another made some acts of piracy legal; ‘privateers’ were sailors (such as Sir Francis Drake) employed by a country to ride around all over the place and disrupt other countries’ trade. All the other nations, of course, considered them pirates and put ‘dead or alive’ prices on their heads, but these people are pretty boring when compared to some of the genuine pirates who terrorised the Caribbean. In many ways, pirates were the first professional celebrities; reasoning that the whole ‘piracy’ business would be a lot easier if everyone would just shit themselves upon sight of them and hand over all the gold without a fight, they put a lot of effort into building up their reputations so that everyone knew who they are. This is one of the reasons why pirates are so famous today, that and the fact that they were simultaneously mental and amazingly charismatic. Consider Blackbeard, probably the most famous real-life pirate and a man who spread rumours about satanic powers and would stick flaming sticks in his beard so he smoked like a demon. Consider Captain John Phillips, whose version of the pirate code (because even criminals have honour of a sort; Phillips’ is one of just four surviving) included an article stating that any man who kept a secret from the rest of the crew was to be marooned on a desert island with nothing but a bottle of water, a pistol, gunpowder and shot. Just to let everyone know who’s boss. And what about Charles Vane, a certified arsehole even by piratical standards whose three-year career netted him the equivalent of around two and a half million US Dollars, which is made doubly impressive by the fact that he never lead a ship with more than twelve guns. For a more expanded (and rather hilarious) look at a few pirates and their stories, I refer you here.

After 1730, the age of the pirates was largely over; the Royal Navy in particular was exerting far more control over the seas and ports, and small pirate vessels were unable to sustain a living. The trade attempted to move overseas, but proved unsustainable in other colonies such as India. The law was finally organised enough to catch up with pirates, and they retreated back into history, leaving only their fearsome reputation and charisma behind. Pirates as we in the west think of them were many things; brave, violent, aggressive, borderline mental, and not the kind of people you’d want to invite to dinner. But one thing that they undoubtedly were, and always will be, is effortlessly, earth-shatteringly cool.

Hitting the hay

OK, so it was history last time, so I’m feeling like a bit of science today. So, here is your random question for today; are the ‘leaps of faith’ in the Assassin’s Creed games survivable?

Between them, the characters of Altair, Ezio and Connor* jump off a wide variety of famous buildings and monuments across the five current games, but the jump that springs most readily to mind is Ezio’s leap from the Campanile di San Marco, in St Mark’s Square, Venice, at the end of Assassin’s Creed II. It’s not the highest jump made, but it is one of the most interesting and it occurs as part of the main story campaign, meaning everyone who’s played the game through will have made the jump and it has some significance attached to it. It’s also a well-known building with plenty of information on it.

[*Interesting fact; apparently, both Altair and Ezio translate as ‘Eagle’ in some form in English, as does Connor’s Mohawk name (Ratonhnhaké;ton, according to Wikipedia) and the name of his ship, the Aquila. Connor itself translates as ‘lover of wolves’ from the original Gaelic]

The Campanile as it stands today is not the same one as in Ezio’s day; in 1902 the original building collapsed and took ten years to rebuild. However, the new Campanile was made to be cosmetically (if not quite structurally) identical to the original, so current data should still be accurate. Wikipedia again tells me the brick shaft making up the bulk of the structure accounts for (apparently only) 50m of the tower’s 98.6m total height, with Ezio’s leap (made from the belfry just above) coming in at around 55m. With this information we can calculate Ezio’s total gravitational potential energy lost during his fall; GPE lost = mgΔh, and presuming a 70kg bloke this comes to GPE lost= 33730J (Δ is, by the way, the mathematical way of expressing a change in something- in this case, Δh represents a change in height). If his fall were made with no air resistance, then all this GPE would be converted to kinetic energy, where KE = mv²/2. Solving to make v (his velocity upon hitting the ground) the subject gives v = sqrt(2*KE/m), and replacing KE with our value of the GPE lost, we get v = 31.04m/s. This tells us two things; firstly that the fall should take Ezio at least three seconds, and secondly that, without air resistance, he’d be in rather a lot of trouble.

But, we must of course factor air resistance into our calculations, but to do so to begin with we must make another assumption; that Ezio reaches terminal velocity before reaching the ground. Whether this statement is valid or not we will find out later. The terminal velocity is just a rearranged form of the drag equation: Vt=sqrt(2mg/pACd), where m= Ezio’s mass (70kg, as presumed earlier), g= gravitational field strength (on Earth, 9.8m/s²), p= air density (on a warm Venetian evening at around 15 degrees Celcius, this comes out as 1.225kg/m3), A= the cross-sectional area of Ezio’s falling body (call it 0.85m², presuming he’s around the same size as me) and Cd= his body’s drag coefficient (a number evaluating how well the air flows around his body and clothing, for which I shall pick 1 at complete random). Plugging these numbers into the equation gives a terminal velocity of 36.30m/s, which is an annoying number; because it’s larger than our previous velocity value, calculated without air resistance, of 31.04m/s, this means that Ezio definitely won’t have reached terminal velocity by the time he reaches the bottom of the Campanile, so we’re going to have to look elsewhere for our numbers. Interestingly, the terminal velocity for a falling skydiver, without parachute, is apparently around 54m/s, suggesting that I’ve got numbers that are in roughly the correct ballpark but that could do with some improvement (this is probably thanks to my chosen Cd value; 1 is a very high value, selected to give Ezio the best possible chance of survival, but ho hum)

Here, I could attempt to derive an equation for how velocity varies with distance travelled, but such things are complicated, time consuming and do not translate well into being typed out. Instead, I am going to take on blind faith a statement attached to my ‘falling skydiver’ number quoted above; that it takes about 3 seconds to achieve half the skydiver’s terminal velocity. We said that Ezio’s fall from the Campanile would take him at least three seconds (just trust me on that one), and in fact it would probably be closer to four, but no matter; let’s just presume he has jumped off some unidentified building such that it takes him precisely three seconds to hit the ground, at which point his velocity will be taken as 27m/s.

Except he won’t hit the ground; assuming he hits his target anyway. The Assassin’s Creed universe is literally littered with indiscriminate piles/carts of hay and flower petals that have been conveniently left around for no obvious reason, and when performing a leap of faith our protagonist’s always aim for them (the AC wiki tells me that these were in fact programmed into the memories that the games consist of in order to aid navigation, but this doesn’t matter). Let us presume that the hay is 1m deep where Ezio lands, and that the whole hay-and-cart structure is entirely successful in its task, in that it manages to reduce Ezio’s velocity from 27m/s to nought across this 1m distance, without any energy being lost through the hard floor (highly unlikely, but let’s be generous). At 27m/s, the 70kg Ezio has a momentum of 1890kgm/s, all of which must be dissipated through the hay across this 1m distance. This means an impulse of 1890Ns, and thus a force, will act upon him; Impulse=Force x ΔTime. This force will cause him to decelerate. If this deceleration is uniform (it wouldn’t be in real life, but modelling this is tricky business and it will do as an approximation), then his average velocity during his ‘slowing’ period will come to be 13.5m/s, and that this deceleration will take 0.074s. Given that we now know the impulse acting on Ezio and the time for which it acts, we can now work out the force upon him; 1890 / 0.074 = 1890 x 13.5 = 26460N. This corresponds to 364.5m/s² deceleration, or around 37g’s to put it in G-force terms. Given that 5g’s has been known to break bones in stunt aircraft, I think it’s safe to say that quite a lot more hay, Ezio’s not getting up any time soon. So remember; next time you’re thinking of jumping off a tall building, I would recommend a parachute over a haystack.

N.B.: The resulting deceleration calculated in the last bit seems a bit massive, suggesting I may have gone wrong somewhere, so if anyone has any better ideas of numbers/equations then feel free to leave them below. I feel here is also an appropriate place to mention a story I once heard concerning an air hostess whose plane blew up. She was thrown free, landed in a tree on the way down… and survived.

EDIT: Since writing this post, this has come into existence, more accurately calculating the drag and final velocity acting on the falling Assassin. They’re more advanced than me, but their conclusion is the same; I like being proved right :).

Attack of the Blocks

I spend far too much time on the internet. As well as putting many hours of work into trying to keep this blog updated regularly, I while away a fair portion of time on Facebook, follow a large number of video series’ and webcomics, and can often be found wandering through the recesses of YouTube (an interesting and frequently harrowing experience that can tell one an awful lot about the extremes of human nature). But there is one thing that any resident of the web cannot hope to avoid for any great period of time, and quite often doesn’t want to- the strange world of Minecraft.

Since its release as a humble alpha-version indie game in 2009, Minecraft has boomed to become a runaway success and something of a cultural phenomenon. By the end of 2011, before it had even been released in its final release format, Minecraft had registered 4 million purchases and 4 times that many registered users, which isn’t bad for a game that has never advertised itself, spread semi-virally among nerdy gamers for its mere three-year history and was made purely as an interesting project by its creator Markus Persson (aka Notch). Thousands of videos, ranging from gameplay to some quite startlingly good music videos (check out the work of Captain Sparklez if you haven’t already) litter YouTube and many of the games’ features (such as TNT and the exploding mobs known as Creepers) have become memes in their own right to some degree.

So then, why exactly has Minecraft succeeded where hundreds and thousands of games have failed, becoming a revolution in gamer culture? What is it that makes Minecraft both so brilliant, and so special?

Many, upon being asked this question, tend to revert to extolling the virtues of the game’s indie nature. Being created entirely without funding as an experiment in gaming rather than profit-making, Minecraft’s roots are firmly rooted in the humble sphere of independent gaming, and it shows. One obvious feature is the games inherent simplicity- initially solely featuring the ability to wander around, place and destroy blocks, the controls are mainly (although far from entirely) confined to move and ‘use’, whether that latter function be shoot, slash, mine or punch down a tree. The basic, cuboid, ‘blocky’ nature of the game’s graphics, allowing for both simplicity of production and creating an iconic, retro aesthetic that makes it memorable and standout to look at. Whilst the game has frequently been criticised for not including a tutorial (I myself took a good quarter of an hour to find out that you started by punching a tree, and a further ten minutes to work out that you were supposed to hold down the mouse button rather than repeatedly click), this is another common feature of indie gaming, partly because it saves time in development, but mostly because it makes the game feel like it is not pandering to you and thus allowing indie gamers to feel some degree of elitism that they are good enough to work it out by themselves. This also ties in with the very nature of the game- another criticism used to be (and, to an extent, still is, even with the addition of the Enderdragon as a final win objective) that the game appeared to be largely devoid of point, existent only for its own purpose. This is entirely true, whether you view that as a bonus or a detriment being entirely your own opinion, and this idea of an unfamiliar, experimental game structure is another feature common in one form or another to a lot of indie games.

However, to me these do not seem to be entirely worthy of the name ‘answers’ regarding the question of Minecraft’s phenomenal success. The reason I think this way is that they do not adequately explain exactly why Minecraft rose to such prominence whilst other, often similar, indie games have been left in relative obscurity. Limbo, for example, is a side-scrolling platformer and a quite disturbing, yet compelling, in-game experience, with almost as much intrigue and puzzle from a set of game mechanics simpler even than those of Minecraft. It has also received critical acclaim often far in excess of Minecraft (which has received a positive, but not wildly amazed, response from critics), and yet is still known to only an occasional few. Amnesia: The Dark Descent has been often described as the greatest survival horror game in history, as well as incorporating a superb set of graphics, a three-dimensional world view (unlike the 2D view common to most indie games) and the most pants-wettingly terrifying experience anyone who’s ever played it is likely to ever face- but again, it is confined to the indie realm. Hell, Terraria is basically Minecraft in 2D, but has sold around 40 times less than Minecraft itself. All three of these games have received fairly significant acclaim and coverage, and rightly so, but none has become the riotous cultural phenomenon that Minecraft has, and neither have had an Assassin’s Creed mod (first example that sprung to mind).

So… why has Minecraft been so successful. Well, I’m going to be sticking my neck out here, but to my mind it’s because it doesn’t play like an indie game. Whilst most independently produced titled are 2D, confined to fairly limited surroundings and made as simple & basic as possible to save on development (Amnesia can be regarded as an exception), Minecraft takes it own inherent simplicity and blows it up to a grand scale. It is a vast, open world sandbox game, with vague resonances of the Elder Scrolls games and MMORPG’s, taking the freedom, exploration and experimentation that have always been the advantages of this branch of the AAA world, and combined them with the innovative, simplistic gaming experience of its indie roots. In some ways it’s similar to Facebook, in that it takes a simple principle and then applies it to the largest stage possible, and both have enjoyed a similarly explosive rise to fame. The randomly generated worlds provide infinite caverns to explore, endless mobs to slay, all the space imaginable to build the grandest of castles, the largest of cathedrals, or the SS Enterprise if that takes your fancy. There are a thousand different ways to play the game on a million different planes, all based on just a few simple mechanics. Minecraft is the best of indie and AAA blended together, and is all the more awesome for it.