游戏邦注：新作《生化奇兵3：无限》（BioShock Infinite）推出在即，Irrational将如何设计游戏中的AI同伴Elizabeth，从而给玩家带来全新的游戏体验？本文作者Taekwan Kim以Elizabeth为研究案例，展开探索性猜想。

接下来的猜想基于两个前提：A）AI同伴所提供的高度真实游戏体验，不亚于玩家在多人模式游戏中与其他玩伴协作互动的感觉；B）AI同伴是大部分同类型游戏中最薄弱的环节，而玩家无法直接控制Elizabeth，这使得前提A成为可能。

《生化奇兵》独创性的叙述游戏情节方式颇受好评，但笔者认为Infinite凭借Elizabeth，还有可能在这方面更上一层楼，更加淋漓尽致。下面就看看我们能从玩家对它的期待中得出结论，并且设想一下这种期待将如何在AI同伴上完美呈现。

BioShock Infinite-Elizabeth

任务委托

高级别的合作需要工作委托。玩《魔兽世界》或者对抗模式的《求生之路》时，我们可以明显地感觉到，某个级别应该做什么工作，而其他级别应该成为这个该工作者的赋能者和辅助者。

然而，如果游戏中唯一的工作就是DPS（游戏邦注：DPS即damage per second，是玩家角色秒间对怪或其他玩家输入的伤害值，这里以合作模式的《求生之路》为例，与对抗模式的《求生之路》截然不同），那么这个游戏就成了追求杀伤数、疯狂丢土炸弹、盲目炸汽油罐的竞赛。这显然有违我们的初衷——我们并不希望玩家在游戏中一味拼命，或者让玩家觉得他的防疫站已经被bot打劫了。

因此工作委托允许各个队伍的成员参与到其他队伍的任务中去，这种参与需要提前计划和仔细考虑合作。但更重要的是，玩家因此可以享受相互支持的乐趣，而不是纯粹的一味DPS。显然，恰当的辅助他人也是合作的乐趣之一。

工作委托就是为其他玩家提供完成任务所需的代理空间（或者时机空间）。例如，如果我们把生命值当成自己对其他玩家的代理空间，就能帮助其他级别的人完成他们的任务；又如，维护tank的生命值让它发挥持续威慑的作用等等。相类似地，Charger玩家冲撞一大批幸存者后，Spitter玩家就能提供真正输出伤害；一个玩家放好炸药炸瞎幸存者，身为Jockey的玩家就可以悄悄拉走幸存者；一个丧失能力可能使另一个幸存者晕倒，从而便利了另一个玩家等等。（游戏邦注：tank、Charger、Spitter和Jockey是《求生之路》中的四种特殊感染者，在对抗模式下可供玩家选择的角色）

沟通的重点在于，根据玩家创造空间的时机来充分感知到对方的行动。也就是说，沟通很大程度上是为了让玩家知道怎么玩一个地图，读懂其他玩家怎么玩这个地图，研究其他玩家如何玩这个地图。

之所以把Elizabeth当成范例，正是因为她显著的优势——在Infinite的游戏设置中，她等同于同伴的身份（至少从能推测到的范围来讲是这样的）。精力/灵药系统和Elizabeth力量的持续释放（这大概很适合玩家）的实现，玩家促使任务委托成为可能，而我们也可以期待利用高度和谐、机遇丰富的地图为任务委托提供便利。

再加上《生化奇兵》着重通过游戏玩法来叙述剧情，这非常有利于既定目的实现。在多人游戏模式下的同伴从来不会有性命之忧，但Elizabeth就没这么幸运了。显然，同伴之间的情感关系在本质和时间长度上是不相同的。但如果这种情感关系在《生化奇兵》里也存在，也许它的份量也不是非常厚重吧。

所以，游戏设计面临的最主要难题就是如何建立起这种同伴关系，使Elizabeth不致于沦为玩家的包袱和累赘（这真是漫长的保驾护航任务，真是令人沮丧的难题），并且与玩家进行“沟通”。

自我拓展

有趣的是，让任务委托变得如此好玩的元素，与维持夫妻婚姻的是同一种情感纽带——至少关于有效的婚姻和关系的研究结果是如此。

每个人都通过与他人建立起的关系来积累知识和经验，这个过程称为“自我拓展”。研究表明，从同伴关系中得到越多自我拓展的人，越能在这种关系中信守承诺和得到满足感。

这个过程也被形容为“米开朗基罗效应”，这是指关系密切的同伴“雕刻”彼此，从而帮助对方达到他们重要的目标。

换句话说，从优势的角度上讲，我们对自己迷失了，我们指望同伴的照顾和帮助（甚至可以把“自我拓展”说成“通过他人实现自我拓展”）。情感关系越密切的夫妻，要区分属于自己还是属于伴侣的特征，就要花越长的时间。

所有这些都是在说，如果玩家通过AI同伴来实现自我拓展，那么就有可能重现多人游戏模式的一个重要元素——情感关系（想一想在《质量效应2》中Joker和EDI之间的关系。我们当然不会有真正的AI，但显然也没必要，尤其是在一个控制良好的环境和情节中）。

从我们已知的信息来看，《生化奇兵3：无限》缺少基因银行（Gene Banks）提供的重置能力。这意味着玩家尝试不同级别或者不同角色的能力受限。玩家通过游戏过程表达出来的倾向极可能保留下来，从而有利于从数据库中收集资料，根据这个数据库调整Elizabeth自身的发展，并针对玩家决策设置奖励。

我们可以从以上推测中得出重要结论：一旦Elizabeth的发展方式与玩家自己的的发展/投资密切相关，玩家就会与之产生实质上的同伴关系（当然，假如Elizabeth这个角色编写得够好—–至少不低于《BioShock》这款游戏的标准）。Elizabeth就不再是一个遥不可及、形同虚设、与玩家毫不相干的跟班，不只是接受这种“管你想不想，这有个雷云，用它打闪电”的命令，而是一个必不可少的资源，一个赋能者和合作者。

平衡难度

也许我们没有想到的是，使自我拓展看似更有组织的东西，却减少了转机事件场景的数量，这些转机事件包括在游戏演示中出现的积雨云和金属球等技能。在游戏的演示版本中，DeWitt 使用相应的能量后，Elizabeth才发动积雨云和金属球这类技能。但这种配合极大地减少了游戏任务的挑战性，这未必是玩家真正想要的。

我们大概也可以把这个问题叫做“the Fatman Problem”。这是指玩家得到像《辐射3》中的FatMan（小型核武器）那样强悍的武器，却往往并不滥用它的功能。

这种倾向产生的原因有二：1）游戏乐趣的减少意味着挑战性也随之下降（当没什么代理可建立的时候），尤其是当玩家已经适应了这种难度的挑战，或者渴望更高级别挑战的时候（与此似类，转机事件变得廉价而无味）。2）为了达到游戏平衡，像Fatman这种过分彪悍的武器装备必然要限制使用次数，这就减少了这类武器装备在常规玩法中的存在感。也难怪大多玩家的技能树中根本没有Fatman的位置，因为这家伙着实干扰了玩家一直在奋力构建的技能树。

回到游戏演示中的那个积雨云的例子，我们可以看到DeWitt勤快地使用闪电/霰弹枪来遏止迎面而来的僵尸群。然后Elizabeth就出场使出必杀技将敌人一网打尽。这意味着如果玩家追求的是刺激性挑战，那么就得当即切断闪电转向而使用其他技能（除非玩家早就盼着那朵浮云了）。

如果Elizabeth使用的力量会消耗体能或者其他类型的能量（普遍推测），那么不仅玩家的游戏进程会被打断，而且还会在这些技能上浪费了能源，这两个负面作用叠加起来，多少破坏了他们寄托在Elizabeth身上的自我拓展方案，或是白白消耗了时机空间。

事实上，这张免死金牌与和以上情况的理解并不是特别相同。因为这张牌有它自己出现的概率，但其出现次数却具有极大的随机性，让它成为常规玩法的一部分只是个幻想。

至于Elizabeth，我们不能求助于这类随机事件，因为这么做妨碍了可靠的任务委托和沟通和谐（如果玩家被一大群丧尸围攻，要是Elizabeth没有使出积雨云，这就是的严重的失信）。此外，通过限制Elizabeth所能使用的资源，简单地控制她使用积雨云的次数，就是把这个技能排除出常规玩法行列之外（又一个Fatman）。所以，解决这个矛盾的技巧是，明智地把这种能力作为玩家技能树的一个完整部分结合到常规玩法中，而又不破坏游戏平衡。（本文为游戏邦/gamerboom.com编译，转载请注明来源：游戏邦）

Thinking About Elizabeth: Part 1

This post is a speculation on how Elizabeth, the fully AI controlled companion in Irrational’s upcoming BioShock Infinite, might be designed in ways that create new player experiences. It’s really just an exploration of AI companion design in general, but Elizabeth was chosen as a useful sort of hypothetical case study.

The following thought experiment, then, is based on these premises: A) a new kind of experience will be reached when co-op play with a fully AI controlled companion has the same level of camaraderie as multiplayer gaming with a friend; B) whereas AI companions are the weakest aspects of most games of similar genre, it is the very fact that the player has no direct control over Elizabeth which makes realizing Premise A possible.

BioShock was praised for bringing about ground-breaking ways to tell stories in games, but I think Infinite has the potential in Elizabeth to do more—much, much more. So, let’s see if we can extract some of what makes co-op feel like what it is, and picture how that might apply to an AI controlled companion.

1. Job Relegation

High level cooperative experiences demand job relegation. If we look at experiences like WoW or versus Left 4 Dead, we find an explicit recognition that certain classes are meant to do certain jobs, and the other classes are meant to be enablers and co-contributors to that job.

If, however, the only job is DPS (co-op campaign L4D, for instance, as opposed to versus L4D), it becomes a competition for who gets the most kills, the most pipes thrown out, burns all the gas cans, etc. Obviously, this is bad for our purposes—we don’t want the player to have to compete with, or feel like his agency has been robbed by, a bot.

Job relegation therefore allows each team member to anticipate what the other team members are going to do, which allows forward planning and deliberate cooperation. But more importantly, it lets players enjoy supporting experiences other than simply just DPS all the time. Notably, properly enabling another is half the fun of co-op.

2. Communication

Job relegation is about providing other players the agency space (or opportunity space) required to do their job. For example, if we think of health as agency space, threat management gives other classes the space to do their tasks; upkeep of the tank’s health allows him to continue generating threat; etc. Similarly, a Charger that knocks down a group of Survivors gives a Spitter the opportunity to inflict real damage; a well placed boom blinds the Survivors and gives a chance for a Jockey sneak a Survivor away; one incapacitation makes another incap more likely, which further facilitates another; etc.

The point of communication, then, is to alert each other as to when and how a player is about to create such spaces. Which is to say, communication largely comes down to knowing how a map is played, and reading/working with how other players are playing the map.

The reason why Elizabeth is a useful example here is her obvious prominence—her status as an equal partner—in Infinite’s gameplay (at least, from what can be gathered). The vigors/nostrums system and the fact that Elizabeth’s powers evolve over time (i.e., possibly tailors to player tendencies) make real, player driven job relegation possible, and we can definitely expect highly tuned, opportunity rich maps for job relegation to take advantage of.

Plus, BioShock’s focus on narration through gameplay bodes well for the stated goals. A friend you play multiplayer with will never have his life threatened, but Elizabeth will. Obviously, the emotional connection with a friend will be different in substance and longevity, but, if the kinds of experiences found in BioShock are anything to go by, perhaps not very drastically in quality.

So the main difficulties lie in figuring out how to create such connections so that Elizabeth doesn’t feel like a dead weight that holds the player back (that is, like a game-long escort mission, or frustrating artificial inflation of difficulty), and in making “communication” really work.

Self-Expansion

Interestingly, the things that make job relegation so enjoyable are the same things that make relationships between married couples sustainable—at least according to this research on meaningful marriages and relationships.

Individuals use a relationship to accumulate knowledge and experiences, a process called “self-expansion.” Research shows that the more self-expansion people experience from their partner, the more committed and satisfied they are in the relationship.

From the same article, this process was descriptively called “the ‘Michelangelo effect,’ referring to the manner in which close partners ‘sculpt’ each other in ways that help each of them attain valued goals.”

In other words, self-expansion means that for assets that we are missing in ourselves, we look towards our partners to provide or help obtain (you might even read the term as “expanding the self through another”). It was found that the closer the emotional connection between a couple was, the longer it took for them to distinguish between characteristics belonging to oneself and those belonging to one’s partner.

All of this is to say that a significant portion of the multiplayer experience will be successfully recreated if the player begins to experience self-expansion through an AI controlled companion. (Think of the relationship between Joker and EDI in Mass Effect 2. Of course, we’re not going to have real AI, but that’s arguably not necessary, especially within a controlled environment and narrative.)

BioShock Infinite, as far as we know from available published information, lacks the respec ability provided by Gene Banks in BioShock. What this means is that the player’s ability to try out different classes or take on different roles within the same game is restricted. Subsequently, it also means that player tendencies expressed through the course of the game are likely to remain, which gives the opportunity to collect a statistics based database from which to tailor Elizabeth’s own evolution and reward player decisions over time.

The important thing to draw from the above is that as long as Elizabeth develops in a fashion which works closely with the player’s own development/investment pattern, the player will experience a substantially real relationship with her (of course, assuming that the character of Elizabeth is well written and well programmed—at least, as much as can be expected from a BioShock game). Elizabeth is then no longer just a detached and unrelated hanger-on that has nothing to do with the player’s build, she is now an integral asset, an enabler and co-conspirator in more ways than just “here is a thundercloud, now use it to strike lightning, regardless of whether or not that was your goal.”

Get Out of Jail Free Problem

Perhaps counter-intuitively, the thing that will make self-expansion seem more organic is to reduce the number of deus ex machina type situations, such as the raincloud and metal ball in the gameplay demo for BioShock Infinite. It appears from the demo that Elizabeth only brings out those skills after DeWitt has already been using their matching power. But the fact remains that they significantly reduce the challenge of the situation, which is not necessarily what the player actually wants.

We might also call this “the Fatman Problem.” When the player has access to something as powerful as the Fatman in Fallout 3, the player tends to refrain from using it. (This player tendency was actually discussed in the first episode of Irrational’s regular interview series, which featured Mr. Todd Howard.)

The tendency arises from two factors: 1) A game is less fun when there is less challenge to be won (that is, when there is less agency to be built), especially when the player is already acclimated to/expects a higher level of challenge (this is in the same way that a deus ex machina resolution to a story often feels cheap and unsatisfactory). 2) Game balance demands that overpowered devices such as the Fatman necessarily be restricted in number of uses, which reduces their presence in regular play. So much so that the Fatman does not figure into most player builds at all, which means that they become an intrusion into something the player has been fighting to establish throughout the course of the game.

Going back to the raincloud example in the gameplay demo, we can see that DeWitt is diligently using electro bolt/shotgun to try to stem the tide of incoming mobs. Elizabeth then appears and provides an essentially overpowered solution based on electro bolt. This means (unless the player was already expecting and waiting for that cloud) if the player wants to get his fill of the challenge, the player actually needs to stop what he is doing and switch out from electro bolt to something else.

If Elizabeth’s use of powers then has a physical or other type of cost (as is widely speculated), not only do we have a situation where the player’s game has been interrupted, we now have wasted resources on top of that, which together would seriously break any sort of self-expansion projected onto Elizabeth. A similar situation in multiplayer games would either be a complete breakdown in communication, or a failed depletion of opportunity space.

Actually, the get out of jail free card is not particularly a useful parallel to understand the above situation. Because the get out of jail free card relies partially on chance for its occurrence, without a hard limit on how many times it can occur, it has an illusion of being part of regular play.

With Elizabeth, we can’t resort to this type of randomization because this prevents reliable job relegation and communicative coordination (if the player herds a bunch of mobs expecting a raincloud only for Elizabeth not to use it, that becomes a serious breach of trust). Moreover, simply limiting the number of times she can use the raincloud by resource restriction has the effect of pulling it out of regular play (like the Fatman). So the trick is to figure out how to sensitively incorporate such abilities into regular play as an integral part of the player’s build without breaking game balance.（source:gamasutra）