Making the Rules: The Scale of a Game

Lately I’ve been working on both Surreal’s current game as well as concepts for future games, and this issue has come up a few times. As you may have guessed from previous articles, the concept of “more for the sake of more” is not something I subscribe to. Game development is always about the allocation of resources and determining where those resources are best made use of. So when it comes to adding details, sometimes there are tough conversations to have about the scope of a game, along with its sibling, the scale of a game.

Gettin' phat and fat in GTA San AndreasThink of the large, open-world of Grand Theft Auto: San Andreas. In this world, the player can travel around 10 miles end-to-end (representing a geographical space around 100 simulated miles long) You can drive along mountain roads, and enter cities and visit a few selected buildings. The game is primarily about getting in a vehicle and driving. When you deal with people at all, it is generally with a group or crowd. Enemies can be dispatched in 1-2 shots and can be destroyed several at a time. Aside from story moments, most of the player’s interaction level is in terms of streets, with objectives that take the player to “that building”. Sure, there are moments inside of buildings such as shootouts, but if we had to give an arbitrary scale to the game, we could say that there is perhaps 20 meters between items of interest in GTA.

Stranglehold-Patch_2Now look at Stranglehold, a game with a much denser environment. Each level is a few hundred meters in length, but the world is much denser. You cannot drive, but you can run from alley to alley and enter more detailed buildings The game is primarily about shooting it out with a half-dozen or less enemies at a time. When you deal with individuals, they take 4-5 shots and sometimes can be dispatched in elaborate ways. The interactive objects, such as pillars that can be destroyed and tables that can be slid across, are much denser in placement. If we had to give an arbitrary scale to the game, we could say that there are about 2 meters between items of interest in Stranglehold.

Now, there is almost no technical reason why Stranglehold could not have had driving, or why GTA couldn’t have had dense, destructible rooms, aside from those teams choosing where to devote their performance, memory and manpower resources. Sometimes gamers looking for the ubiquitous “more” or even aspiring game developers don’t realize that these choices of scale are very real and deliberate. Even the giant team at Rockstar North realizes that if they lavish attention into a single room or cluster of rooms, that can very easily take resources away from making the game better at the scale it was meant to be played… in a car.

Moments where the scale of interaction changes abruptly can often stand out as going against the pace of the game. If the player is cruising through GTA, blowing up entire crowds of people with grenades, when suddenly he has to close in and complete a 2-minute Tekken-style fight with a single bad guy, it’s going to stand out and completely change the feel of the game. Worse yet, to the developers this would probably be an entirely new game mode (and practically a new game), and as a result, be difficult to deliver at the same quality as the main free-roaming game is delivered.

Similarly, if Stranglehold were to suddenly have an area where the player jumps into a car, there would most likely have to be serious sacrifices to the interactivity of that drivable area. That driving sequence would also have difficulty living up to the experience provided in a driving-centric game like GTA.

Sims 2 Changing the type of gameplay can also be jarring when it affects the pace. What if we could walk up to any of the 30 individuals on a GTA sidewalk and start a conversation with him… learn of his likes and dislikes, and perhaps form a friendship or animosity to that individual based on your actions? Cool eh? But is it worth the development time to make that interesting when people are generally cast aside like tissue paper?

However, it is also very valuable to have what Harvey calls “alternation of gameplay”. This can often break the scale rule, such as Blacksite: Area 51 thrusting the player into a helicopter gunner position after a period of time prowling alleys with your squad of three. This is cool, but is often modal, so that detail can be placed at the appropriate scale for the action. Pillars may explode when you shoot them with your rifle from 5 meters away, but when you are firing an emplaced minigun at a building from 200 meters, you’d better see some larger scale destruction.

Games that let you significantly change scale are rare, but often are modal in their own right. The most prominent example of this is Spore, where you start as an amoeba and ultimately represent an entire race as they colonize the entire galaxy. However, it seems clear that as you progress from single-cell life to the actions of an entire civilization that you rather quickly leave the basic activities of feeding and mating behind. This follows, because it is unreasonable to expect the player to care about a single grain of sand once there is an entire beach to explore…

Bully vs. Harry Potter

BullyA while ago I was talking to Director of Design Richard Rouse along with some of the other Midway studio creative directors about our experiences with Bully. In my case, I really wanted to like it, but only played a few hours before giving up. Since it was blessed with many high reviews (the Gamerankings score settled at around 87%), I was left wondering… “What am I missing?” While we’re always in favor of immersing ourselves in new experiences and gameplay, there’s something about it that wasn’t clicking:

  • Boarding school culture: While the setting may be attractive to 30-something English males (as Simon Woodroffe of Midway Newcastle and Creative Director of Wheelman) pointed out with mentions of Billy Bunter, Jennings, and Ripping Yarns), as Americans we don’t really share the familiarity (hell, I’d never heard of any of those). Not only is the setting something we can’t identify with, it feels more like the world is a conservative culture reminiscent of the 1950’s, but with none of the music or nostalgia to go with it.
  • Class attendence: For me, what gave me the most negative reaction in Bully is the requirement of attending class. Racing to get to class on time is something I didn’t particularly enjoy 20 years ago, so I don’t particularly want to do in a game. If the class activities were more integrated with the regular gameplay, it might have been a bit better, but what bothered me was being forced into a schedule. Constantly being hounded to get to class or that told that I’m violating curfew (and having to avoid the “enforcers” as a result) distracted me from the simple pleasures of exploration (a critical component for open-world games). Since running across campus took nearly the entire couple of “hours” you had between classes, I always felt under the gun. In fact, it reminded me of GUN in a way, which kept pushing me to finish the story rather than have my own fun. A batter choice would have been to drop the player off at the school a week before classes began, to remove some of the schedule and population density while you get your feet wet.
  • BuffyUnattractive lifestyle: While it was generally done for laughs, the characters you deal with early on are all complete losers… You have to help the nerd to the bathroom so that he doesn’t wet himself, you date the ugliest girl in school… your only “friend” is a totally unappealing jerk. In the end, this was enough of a turnoff that I just stopped playing. From trailers and the like it seemed apparent that there was “better stuff” to build up to, but the game did not taunt me with them at all… I never met any cool people, and even attractive women weren’t anywhere to be seen. Bullworth Academy just didn’t position itself to be a place that I wanted to become the king of.

 Harvey Smith of Midway Austin (and Creative Director of Area 51: Blacksite) rightfully pointed out that high school has been a successful setting of great things like Buffy the Vampire Slayer and the Ultimate Spiderman comics. Richard noted that the high school of Buffy was populated by attractive, always-witty teenagers that killed freakin’ vampires. Those California high schools you see in TV and movies are probably some of the most idealized environments you’ll ever see.

Harry PotterThe comparison was also drawn with Harry Potter, which also depicted a “traditional” English boarding school. However, to me the appeal of Harry Potter in its earliest installments (in particular The Sorceror’s/Philosopher’s Stone) was the fact that while Harry was placed in a traditional kid’s horror scenario (first day in a new, unfamiliar school) he succeeds in ways that kids could only dream of:

  • The Center of Attention: Harry was unique and special, and everyone knew it. Kids admired him, and most teachers liked him too. People knew who he was, which paved the way for his ongoing special treatment.
  • A Low level of Conflict and Tension: In the early stories, any negative situation didn’t last long. While most tales in a school setting end the second act with a moment where the main character is suddenly taken out of his or her comfort zone (oh no, the bully has the upper hand, the cute girl is laughing at him/her), in Harry Potter, there is no extended moment of tension. Even the clear antagonists don’t get the upper hand for very long.
  • Frequent Success: Harry is a natural champion at sports, and manages to succeed in class without really “trying”… either through luck or magical destiny, his success is fated to be. He even has the best “car” in the form of his pimped-out witches’ broom.

I certainly can’t discount the fact that Harry Potter has very clever writing and appeals to a wide age group, but when you compare school tales like Bully to those of Harry Potter, you can see that there is a lot that makes kids love those stories.

Stranglehold and Art of Midway

John-Woo-Presents-Stranglehold-PS3We’d like to congratulate the team at Midway Chicago for completing Stranglehold for the Xbox 360! It’s been spotted on store shelves around here, so obviously that’s the official sign! We’ve been playing a lot of it as it approached completion, and it’s a really fun game. They really executed well… It isn’t just about mass destruction, but about using the world around you and gaining the high ground and playing with style. The game rewards you for being the coolest you can be.

We should also call out the incredible work of the Surreal FX team that appears in the game. Every column, chair, and statue all have all been translated into a visual symphony. Perhaps the game isn’t just about mass destruction, but in Stranglehold, even fruit can be capable of dazzling moments. Check it out!

art of midwayAlso, if you dig the visuals of Stranglehold, or if you liked the creepy vibe of The Suffering, you should check out the new Art of Midway book now available! This is concept art on overdrive, including some incredible work from our own Garrett Smith and Ben Olson. These guys create entire worlds with the sweep of their pens (or mice). This is only a sampling of what we see everyday… Thanks also to the Midway art directors for putting this together. Fantastic stuff.

 

Archive 4: Analysis of Diablo 2

This article was written out of necessity back in 2005… I was looking for a new gig and one studio asked for, as part of its application, a paper analyzing one of several possible games. Diablo 2 was on the list. Great timing! I had gone from X-Men Legends, where I learned the ups and downs of action RPG’s to working on Lord of the Rings Online, where discussions of scope and the feasibility of various online choices was the topic of the day. Both games set a lot of speculation stewing in my head about what could be done with the Diablo formula and why it was successful in the first place.

Analysis of Diablo II

by Patrick Lipo

Introduction

When the first Diablo was being previewed in 1995, most people (myself included) were blissfully unaware of its all-out potential. “I played that exact same game on mainframes 10 years ago,” we’d say, patting ourselves on the back. While we were congratulating ourselves, we had forgotten how those games had something that kept us playing and playing.

Blizzard could have simply created a polished copy of Rogue, Moria or Hack and done well, but they managed to refine the experience even further. Diablo was about giving gamers what the wanted, or perhaps what they needed, whether they knew it or not. Building off that success, Diablo II was able to add significant new features without spoiling what the original did right.

What Was Done Well

Simple World Presentation

2D may be “dead” to some, but the use of a 2D field was key to Diablo’s initial accessibility to millions. Everything the player needed to know about his surroundings was right in front of him. North was always up, just like a map. Yet, the isometric view and the 3D-rendered sprites kept the game from looking old. The Sims made a similar choice, and enjoyed similar ease-of-use.

Simple Controls

Click where you want to go. Click what you want to attack. What could be simpler? What Diablo I & II offers is a intuitive, rhythmic, and even mindless player experience at the lowest level. This allows the game to transcend the moment-to-moment battles and make people think about longer-term goals, such as completing the dungeon or gaining the next level. They could have added more moves to the player character (as Blade & Sword attempted), but would have clouded what worked so well, and pushed the emphasis to abilities and loot.

Frequent Rewards

From the very first Quill Rat slain, the coins spew forth, highlighting the strong cycle of rewards in Diablo II. While combat with a single opponent is simplistic, each enemy carries its own surprise contents. Who cares if a tiny Fetish unrealistically explodes like a piñata filled with gold, weapons and armor? Each and every kill feels different and rewarding because the player gets the pleasure of collecting new spoils, and rooting through a full inventory of randomly-generated items can be like a miniature Christmas morning.

The level progression curve is equally rewarding. While an MMO or pen-and-paper derived RPG such as Baldur’s Gate must space level advances with huge sessions of play, Diablo II manages to reward the player often, beginning at about five minutes and smoothly progressing towards around an hour. These frequent level-ups give the player yet another gift-unwrapping session of choosing which skills to acquire or advance. And while another game might provide finely-granular skill points to allocate, each Diablo II skill improvement is noticeable, with a beefy jump in damage, number of minions, or power duration.

Identifiable, Overlapping Goals

A major force in Diablo I and II’s long-lasting appeal is their presentation of goals. The player’s quest objectives are bold and easy to understand, such as “go here”, “find this” or “kill all of X in this area”. Beyond quests, the player can easily identify personal goals for his character, such as “level up”, “get this high-level spell”, or “become powerful enough to wield this weapon”. All these objectives are dangled in front of the player like carrots on a stick… You go into a highly-populated dungeon and you know what to do. You look at your skill tree and you see what prerequisites you need to summon an Iron Golem. Check your inventory and you see that sword that you just need three more points of strength to wield.

Coupled perfectly with this is the way that all of these goals overlap. In some games, the completion of a level gives the player an opportunity to catch their breath and consider quitting their session. In the Diablo series, the completion of a dungeon may bring you most of the way to earning another level, encouraging you to finish it off. However, once you earn that level, you might be halfway through another dungeon, drawing you to player just a bit longer to finish that up… And so it continues.

My first awareness of this dynamic came from playing the original Civilization, which had a similar loop of drawing the player from completing one more unit to finishing up that last attack before quitting for the night. Encouraging this sort of compulsive play behavior is not desirable in every type of game… Tetris’s strength comes from the ease of picking it up for a quick game, and massively-multiplayer games become more expensive to host if their players are active for 16 hours a day. However, for games such as Diablo II and Civilization, the goal structure had the effect of keeping people playing until the light of dawn began streaming through the window…

Randomness and Repeatability

The random generation of items and dungeons in Diablo II is something that outwardly sounds like a nice bullet-point for the sales flyer, but ultimately is integral to the series’ enduring presence. The dungeons have enough variation to make successive plays through (with the same advanced character or an entirely new class) different enough to keep the sense of discovery, but they are not so random as to make the dungeons appear “patchwork” (as seen in the PSP release of Untold Legends). The monsters have a sliding-scale difficulty that helps them remain challenging throughout your replay curve. The items have a fantastic, smart variability that provides statistics and powers that are interesting at the times you really want them. That last feature is something that Dungeon Siege had difficulty replicating (where you often saw Colossal Two-handed Mallets of Wisdom™ or Magic Wands of Excessive Strength™).

Integration of the Meta Experience

The effort that was put into making Diablo II replayable was exploited to the fullest in providing a metagame as well. Once the player completes the full story, it wraps almost seamlessly into the next play-through at a higher challenge level. The advancement curve is such that multiple completions are needed to fully experience everything a class has to offer (and even then there are other classes to explore). This embrace of the player’s experience above and beyond a single telling of the game narrative is something that more games should incorporate.

Minimizing Dead Playtime

One final element that helped give the Diablo series appeal was its conscientious reduction of dead time at any cost. Most RPG’s have some measure of uneventful busywork or travel, but elements such as the Town Portals virtually eliminate any dead travel time in the game. RPG purists doubtless were infuriated at this break with “reality” and “world sense”, but this addition had a far, far, far more positive effect on the player experience than a negative one. Diablo II added sprinting and item highlighting that identified and alleviated tedious bits that existed in the first game, showing that the developers considered this issue important to track down and solve.

What Could Be Improved

More Random Side-Quests

The randomized content of Diablo II is inspiring, as is the simplicity of their quests. One thing that I would do to maximize the value of such a powerful and versatile system is create far more simple side-quests than the game originally provided. The content structure and world layout of Diablo II makes a natural potential for creating hundreds of quests with variable properties that an industrious (and thorough) character can embark on. The component-based map structure allows the game to sprinkle quests into almost any map, each with a named monster and a rare or unique drop, so that adding new dungeons to a previously featureless play zone can provide an entirely new feel. There could be only a limited number of quests available for each play-through, so that it might take the player dozens of characters to see all of the possibilities.

These side-quests could also work with Diablo II’s replayability. By tracking the player’s completion history with different characters, the game could open up specialized quests on subsequent run-throughs. Complete the paladin on the hardest difficulty and your next character might get some holy artifact. This could bring more long-term goals than Easter eggs like the cow quest already provide.

Feedback for Hit-or-Miss

A difficult issue with real-time games that use to-hit rolls is what to do when the character misses his attack. Typically, a miss is shown as a normal hit with no effect or sound. Diablo is this way, allowing the player to click frantically at an enemy, but with only some percentage of the attacks resulting in damage, the rest passing through uneventfully. The player feedback on this is weak, resulting in a little bit of mystery around what is a “good” or “bad” attack total.

Having taken on this issue in the action-RPG X-Men Legends, there are a few things that can be done to help better represent it to the player. The first is to play a “dodge” or “parry” animation on the opponent that shows that player why damage was not done. This can be exciting, adding in new motion to the interaction, but it must be done carefully to avoid confusing the player (for example, big dodging motions might make the player think that the AI is doing something to keep away from him, as though he is doing something wrong). It can also put new pressures on the character animators, particularly if you wish to synchronize the animation with the incoming attack (although this is less necessary with Diablo’s smaller characters). Finally, in a game with many attacks coming into a single target, deciding which ones to respond to can become almost arbitrary.

In X-Men the above was impractical due to memory and manpower limitations, so an alternate approach was taken. A failed attack roll is deemed a “weak hit”, with almost no effect and an unsatisfying “thup” sound. For successful hits, an effect is selected from a set of increasingly intense impacts, depending on how much the player’s attack totals exceed the enemy’s defense. In addition to the hit sound, a secondary “rumble” sound is mixed in to give extra “oomph” to powerful hits. The result of this tactic is that when the player first meets a new creature that is fairly tough, he does weak hits, but as he begins to gain experience and outclass it, he is rewarded by much more powerful effects to go with his increased damage-dealing.

More Dungeon Interactivity

Diablo dungeons are very good at providing exactly what they need as far as functionality. Their interactivity needs are very simple… a key may unlock a door or trigger an animation, flipping a bit in the dungeon and little else. This makes “what you do” in the dungeons fairly limited. By adding a few moving elements such as sliding walls and mobile platforms, certain situations could gain more of a time element, such as protecting a caravan or moving through an area before a wall crushes the player.

Also, if destructible structures and walls were added, player spells could have much more tangible impact on the world, and monsters would be able to smash their way through obstructions for dramatic effect.

Encounter Generation

At this point I’ve given suggestions on content, presentation and technology, but played it fairly safe (any schlep can say “more quests!” or “break stuff!”), so I’ll add something that might have more impact on Diablo II’s gameplay. The standard play structure of Diablo II involves creatures that sit and wait for you to clear them out, after which an area is empty until reset. For the sake of contrast, this could be enhanced by creating encounters that come to the player instead. These could be used to occasionally liven up travel through a cleared-out area, or add tension to certain objectives with ambushes, retaliations or pursuits.

These encounters would need to be generated with the same care as the rest of Diablo II’s randomized content, fitting with the appropriate biome, challenge level and terrain features. They would also have to be provided at carefully timed moments, so as to not betray the feeling of accomplishment that a player feels when walking through an area he devastated. A useful technique would be to let the player in on exactly what is happening by announcing the attack with a battle cry or even a special title (“Raptor Vengeance!”) when one is triggered.

In the case of random quests, these encounters could greatly enhance the sorts of events that can occur. Finally, generated encounters could potentially provide the game with the feel of hand-crafted content without the manpower and testing challenges typically experienced by heavily scripted games.

Conclusion

I hope that this analysis of Diablo II was not so drawn out that I lost you two pages ago. The game at its core is so simple, yet it did so many things right. It is amazing that more games haven’t benefited from the lessons it brought to the industry.

One Last PAX Experience

I hit PAX on Friday and Saturday, so I should post my notes before they become irrelevant…  It was my first PAX, although I’ve been to many similar con-type events in the past.

General show:

  • With its unabashed “nerdcore” attendee list, PAX is better described as a mini-GenCon than a mini-E3. They have an impressive size for being a fairly young show, but it still is very much centered around fandom of the Penny Arcade comic. The sessions with the authors and on the PA game were some of the hottest tickets, as opposed to other sessions talking about more “serious” topics of development.  Not surprising, it’s not supposed to be a GDC or anything, despite heady topics about PR and episodic content.
  • On the upside, it actually had a fairly impressive turnout of games in playable form, including many that I hadn’t seen before in any form. I assume that falling at the same time as Leipzig gave the publishers some ready-made material to show.
  • Aside from what I mention below, there was a great spread of playable games:  Haze, Eye of Judgment, Metroid Prime 2, Conan (console), Heavenly Sword (a new demo), Warhammer Online, a big America’s Army thing, and several dozen more I’m not thinking of here.
  • Nintendo, Microsoft, Sony and EA all made an appearance, which is impressive given recent news that E for All won’t have that sort of backing.
  • Overall PAX surprised me with an air of “legitimacy” as a serious show. It would take a couple more years, but if it ultimately balloons into a notable national event, it’ll be cool for Seattle. Continue reading One Last PAX Experience

PAX Day Friday!

Surreal sent the entire company to PAX (the Penny Arcade Expo) on Friday…  It was conveniently located in downtown Seattle this year, at the Washington State Convention Center, not too far away.  A few of us actually found a reason to take the semi-famous-but-usually-useless Seattle Monorail (it only travels end-to-end from the Space Needle to downtown, not very far).  The rest of us found that it wasn’t that far of a walk… and we were able to stop at Shorty’s for a dog in the process!

Some of the guys have some impressions that will be posted shortly.

Refueling in Room 130

I should talk a bit about my experiences with the academic group that made up Joystick101 and the local groups around it.  As I reached 2004 and was just finishing up X-Men Legends, I was getting pretty burned out on the industry…  11 years of making varieties of shooters at Raven was entertaining, but was growing into a somewhat single-note affair.  Around then, Nathan McKenzie, an incredible gameplay programmer I had been fortunate to poach from a college back in (I think) 1996 was acquainted with a lot of the game academics around the University of Wisconsin.  After an awesome run completing Soldier of Fortune in 2000, Nathan had taken a couple of years off and did something of a journey of self-discovery…  He came back to work on Quake 4 in (I think) 2003 with a lot of academic knowledge and a pretty unique view on games. 

Anyway, Nathan introduced me to the UW academics that had been studying games…  something I had no idea existed.  They were an incredibly interesting group, including Kurt Squire, Constance Steinkeuhler, Alice Robison and notably Professor Jim Gee.  Every week a group of them, including a number of other graduate students in departments such as Education, Linguistics and English, would gather in a game wonderland known as Room 130.  Every week these folks would gather and play a new game, observe and talk about them.  These were not the hardcore gamers that I had grown accustomed to interacting with, although they loved games with an equal fervor.

 Coming from a fairly practical point of view on games and development over the previous 11 years, I felt refreshed.  I didn’t ultimately “switch” to an academic perspective as much as Nathan did (he’s doing awesome, more power to him!), but my eyes opened a bit, knowing that there were more angles to look at games than I had realized…  Not everyone was searching for that 20-levels-8-weapons-12-enemies magic formula that seemed so common out there.  It was just what I needed to help me explore other genres and places. 

So, to the Room 130 folk, my thanks.

Making the Rules: Great Enemies

complicated_flowchartPreviously I’ve talked about how games adjust AI difficulty because of the need to fulfill the player’s fantasy, and provide them with success and positive feedback. This time I’d like to talk about perils and pointers for creating good combat AI. Now, while many articles that wish to address “great AI” contain heavy jargon or equations and diagrams depicting line of sight, or reticular splines or some such, let’s put that aside for now. It can be a great deal simpler than that (although in some ways more challenging).

Out of Sight, Out of Mind

Imagine dropping a player in a sprawling maze… hedgerow, factory, prison, whatever… that is impossible to be known beforehand. Within there is one incredibly realistic, human-like AI… It operates on its senses, with no unfair information about the maze or the player, but it executes on some crazy supercomputer with a million factors that it takes into account, from its knowledge of combat tactics to its own preferences and personality. Hell, let’s even keep track of what it had for breakfast in case we want to simulate a chance of it having an upset stomach. This AI’s job is to start searching for the player and make assaults as he moves through the maze. For a moment, as we watch the AI, we can see it moving through the maze, tracking the player’s scent, thinking about how to flank him… when it hits a fork in the path, it decides to go left or right based on tactical decisions, or its own tendencies, or whatever a human-like AI should do. Perhaps it has a human-like idiosyncrasy like alternating… Whatever. The important thing is when it finds the player, whether by crafty wiles or just dumb luck, it switches to combat tactics and starts attacking the player without warning, pressing any advantage it can. When it is out of the player’s view, he is completely stealthy, undetectable until he encounters the player again.

Wolf3dNow imagine this experience from the player’s perspective. He’s moving through the maze, starting to get familiar with his surroundings. Assuming the brilliant AI is quiet like he is, the enemy could be around any corner. The first time he encounters him, the attack could be anywhere, behind, ahead… who knows. If the AI is particularly crafty and sets up a sniper ambush, the player could die in a single shot to the head. To the player it’s a chaotic, unpredictable experience… Perhaps a fun one for some, perhaps not.

Now let’s replace the AI with a more rudimentary version, one that makes more random decisions about what path to take while moving through the maze. This is sporadically punctuated with the AI taking the best path to the player, using perfect information. The enemy will still use intelligent tactical decisions once the player has engaged it in combat, but when it is out of the player’s sight, the AI is entirely artificial. For the player, assuming the general frequency and predictability of the enemy appearance is similar, very few audience members will notice the difference.

Now let’s go even further, and replace the AI with a spawning routine that creates an enemy at the edge of the player’s awareness at a similar frequency and predictability as either of the other approaches. Certainly there are a few cases where it would make a wrong choice, such as spawning the enemy from a dead-end, but how often would this become apparent to most players? .

Now what point am I making here? That “real AI” is worthless? Of course not! When the enemy is within the player’s view, it needs to act extremely effectively, to provide the player with sufficient combat challenge and to keep the illusion up that this is human-like behavior. However, once the player has lost all perception of the enemy’s movements, there is a significant drop-off in the impact of sophisticated AI on the player’s game experience… That enemy could go off and play chess, consult his favorite tracker’s handbook or compose humorous limericks about the death of the player, but none of it makes much of a difference if the player is not aware of these activities. And it doesn’t advocate delivering “good enough”, it’s just that we could be using that supercomputer for better things.

A Pinch of Player Feedback

Soldier of Fortune 2-1Of course there are better ways of selling an interesting “hunt” scenario between a player and an AI. The game might have remote cameras out in the world that allow you to sporadically see his activities. The enemy can leave a trail that you can pick up. He can make noises that might give away their position or distract you. These additions almost universally add additional player awareness of the AI’s activities when he is out of sight.

Sure, you can add some clever AI tactics that go beyond spawning… he might feint in one direction to lure you off, then work around and flank you. However, consider that we are adding to events in a chaotic, confusing combat situation to begin with. How would most players feel if they went towards an enemy who disappeared, appearing not much later to shoot him in the back? He might feel confused, or cheated, like the AI did something illegal. There is no satisfaction to be gained by guessing the enemy’s next action and planning accordingly. There is no learning process to “outwit” the opponent, nor is there any way to increase one’s skill to defeat him, aside from simple reflex improvement such as firing a gun accurately.

The development of most game features require the creator to balance of the investment of time and computer performance, versus the gameplay value created. No feature is free, and in a shooter, if the AI programmer spent all their time creating AI’s that can independently recreate all the works of Shakespeare, the time would generally be wasted… such effort and horsepower doesn’t help the player… this is a game about combating the enemy. Back when I was working on Soldier of Fortune 2, there were some enemies that had the ability of tossing clips to each other if one ran out of ammo. However, nobody knew that feature existed. Why? Well, the clips were never exchanged unless the two enemies were behind cover, completely out of sight. Also, the ammo level of any individual enemy was never a significant issue in the game, since fights tended to be very short and deadly. This was a time to invoke a cardinal rule of game development: Features that do not notably affect the player experience are usually not worth implementing.

Half Life 1Contrast that to the AI in the first Half-Life, which critics and consumers unanimously celebrated as one of the most significant contributors to their enjoyment of the game. In Half-Life the enemies did all sorts of things, from flanking you to spotting your thrown grenades and responding accordingly. However, combat against the deadly Black Mesa soldiers was a very hide-and-shoot affair, so there would have been little opportunity for the player to understand their tactics and smarts. However, some exceedingly smart individual at Valve decided to give the player a radio that intercepted the soldier’s communications, which gave the player a window on their reactions and strategies. Sure, it would have been even more challenging for the player if he had absolutely no clue to what the enemies were going to do next, but it is far more impactful to the player’s experience to allow him to understand how smart the enemies are. Arguably, beyond every other feature the enemies in Half Life had, the radio was the single most significant invention of that game.

Enemy communication of their intent has been used in other games, such as Halo, where the slightly comical alien grunts would spout exclamations like “there he is!” or “where’d he go?” when they observed a specific situation. Metal Gear Solid soldiers talk to themselves, saying “what was that noise?” and so on. Of course it’s not realistic, but it makes things more fun. Concealing those mechanisms actually creates a less compelling experience than when you lay out the rotating gears in front of a big window that the player can see.

Great AI lives in the player

mgs2iceSo if a more human-like opponent leads to unpredictable, and often unsatisfying behavior, and realistic, limited information plunges the player into a chaotic, random-seeming experience, what is the player asking for when he or she is asking for “better AI” or a “smarter” opponent? The answer to this harkens back to a previous point, that the player wishes to fulfill a specific fantasy that they have. They wish for their opponents to respond as they imagine they would in their fantasy. In the case of a super-spy fighting against armies of henchmen, it’s a set of opponents that appear to fight against the player effectively, yet die or fail to kill the player at appropriate moments so that the player can feel powerful.

In a player’s fantasy, an enemy is still capable of many things. There is a great deal that a gamer can imagine his electronic opponents doing to try to outsmart him. This includes flanking the player, hearing noises and investigating, changing ammo types, and spotting and responding to thrown grenades. In fact, it could be said that a large variety of actions at the enemy’s disposal is what might make him seem “smart”. However, again, with limited information confounding the player’s ability to appreciate this rich palette of AI options, there is but one avenue to make a character seem intelligent… we must inform the player of some of the choices that are being made while they are being made, so that the player can feel even cooler when taking them out.