作者：Pascal Luban

现在我们谈到免费增值游戏（free-to-play，以下简称F2P）所指的并非一种新游戏类型，而是一场重塑游戏产业的变革，它深刻影响了游戏的市场营销、发行、硬件制造商，当然还有设计师和开发者等各个环节。F2P为游戏产业带来了福音，它扩大了游戏玩家规模，复兴了一度陷入低迷的游戏产业，使开发者获得了为玩家创造全新游戏体验的机会。

F2P游戏不需要所有内容均到位时才发布，大部分内容可以等到发布后再逐渐增加。韩国网游公司Nexon曾统计称其F2P游戏只要拥有50%的成品内容就可以上线，而社交游戏开发商Playfish的游戏甚至只需要20%的内容就可以发布！

F2P游戏初期只需要低成本投入的原因还包括其开发技术、工具的简单及平价。另外，由于游戏免费开放服务，玩家一般也不会苛求游戏质量。

这类游戏的多数用户属于休闲玩家，他们对游戏的要求比资深玩家更低。但是，F2P游戏的开发成本正呈现上升趋势，那些锁定硬核玩家的游戏尤其如此。例如，《英雄联盟》的产品质量就堪比零售视频游戏。

F2P游戏的一个成功诀窍就是采用强大的数据分析系统，搜集有关玩家喜好和操作习惯的相关数据。

开发者会根据这些数据以及玩家的反馈意见，修复游戏中的漏洞，不断增强游戏的吸引力。假如游戏理念很出色，其失败的风险就会有所降低，而这却正是困扰传统游戏开发领域的一个大问题。

概述F2P的总体情况后，我们现在要探讨的是这种游戏的核心设计理念。也许有人认为《FarmVille》这种社交游戏的设计方式与《Combat Arms》或《英雄联盟》之类的硬核游戏并无相似之处，但无论是哪种题材，F2P游戏都要遵从一定的基本设计原则，这正是本文主要讨论的内容。

F2P与传统游戏的关键设计区别

首先让我们看看F2P游戏与传统游戏运营模式的差异。

传统游戏设计师只需要考虑如何取悦玩家，而F2P游戏却要兼顾玩家的娱乐性和项目的盈利性。Klei Entertainment创始人Jamie Cheng的看法是：“不要让用户为娱乐付费，而要用娱乐让他们主动掏钱。”

那么F2P游戏设计师须奉行的准则又是什么？

提供即时的满足感。F2P游戏虽然移除了用户体验游戏的价格门槛，但也带来了一个新挑战，即如何说服玩家持续体验当前的游戏，避免玩家因无法获得快感而转向其他游戏。

在付费游戏领域，玩家因为已经在一款游戏中投入成本，就算他们对游戏的第一印象不佳。也不会轻易在数分钟时间内给游戏判死刑，他们会在体验数小时之后再决定是否要放弃游戏。

但换成免费游戏后，玩家与游戏之间就不存在这种“利益攸关性”了。他们一文不花就能玩游戏，如果游戏无法带来即时的良好体验，他们就会果断离去并另择他处。因此F2P游戏的首个设计难关就是提供能够让玩家“上钩”的即时满足感。

设计持久的游戏体验。在F2P游戏领域，用户体验游戏的时间越长，就越有可能花钱买道具。但设计一款可让玩家持续数月活跃于其中的游戏实非易事。除了MMO和多人游戏之外，最近几年的设计趋势就是为玩家提供紧凑而简短的游戏体验。因此我们必须开发经得起时间考验的游戏，我们的设计目标就是让玩家经常逗留于游戏世界，在数月时间中经常短暂性地回访游戏。

针对新用户设计游戏。虽然MMO和FPS等一些F2P游戏锁定的是特定群体，但许多F2P游戏服务的对象却更为广泛，其中多为妇女和低龄玩家群体，而这两个群体都不擅长玩传统视频游戏，他们的游戏动机和期望与硬核玩家截然不同。而更年长的玩家，例如30岁以上群体，他们多数已经成家立业，生活较为繁忙。对他们来说，游戏时间非常有限。女性用户则喜欢将游戏视为一种增进人际关系的渠道，而并非满足竞争欲望的工具。F2P设计师需确定好自己的目标用户，了解他们的游戏习惯和期望后才能动工。

优秀F2P游戏的核心设计准则

易用性

新玩家对游戏的发展极有价值，开发者通常都会想法留住初来乍到的玩家。

运行游戏的便捷性。如果玩家登录游戏需要执行的步骤越多，就越可能失去耐心而退出游戏。这也正是Facebook人气如此高涨的原因之一，该平台上的游戏无需用户注册、下载或者安装任何应用，玩家只需要点击一个链接就能立即玩游戏。

我将以Unity 3D为例说明让玩家采取额外操作所带来的影响。

Unity针对Facebook开发了一个很强大的插件，它的安装步骤极为简单，占击要一次点击安装，并且不夹带广告内容，玩家就能安装该插件。而据Unity公司首席执行官David Helgason在2008年所称，过去有40%玩家在运行游戏时没有完成安装过程。

当然，这个比例也要取决于不同的游戏类型。出色的游戏安装完成率还会更高。问题就在于许多PC用户对安装程序这件事情非常谨慎，如果再让他们在体验游戏前输入个人信息，或者下载并安装应用程序，这种情况势必让他们大为扫兴。

但也有一些特例——《冒险岛》或《Combat Arms》这类极佳的F2P游戏就要求玩家输入完整的个人信息，并下载一个庞大的客户端。但要知道，这两者是在市场上鲜有竞争对手之时就已发布。

这个问题有两个解决方案：

*在Facebook或者Bigpoint门户网站等现存平台上发布游戏，利用Flash或HTML5技术开发游戏；

*开发可运行于网页浏览器的游戏。《战地：英雄》就采用了这种方法。

指导用户操作游戏。如果玩家在自己不熟悉的游戏中手足无措，那他们很快就会退出游戏。许多F2P游戏都会在初步阶段先引导玩家探索基本的操作方式，限制其接触更高级的功能。这样可以避免玩家深陷大量自己不了解的功能而茫然无措，盲目操作游戏的情况。但需要注意的是，一下子提供太多选择也会让许多休闲及非游戏玩家抓狂。

在初级阶段限制操作选项并不会降低游戏吸引力。游戏当然可以融入更多更复杂的选项，但只能逐步展开这些内容。游戏的设计目标应该是让玩家经历良性的螺旋式学习过程，即：1）我知道自己要做什么；2）我很容易执行操作；3）我成功完成操作；4）我获得奖励；5）我发现了短期目标并知道如何实现。总之不可让玩家一开始就失败，这是让他们持续探索游戏的一个重要前提。

还有另外两种设计功能可以辅助这种指导策略：

*设置进度条：玩家按新手教程指引的顺序发现新功能时，进度条就会逐步填充完整。这种简单的进度条可以让玩家知晓自己的游戏进展，激发他们的好奇心，激励他们去探索所有的游戏功能。

*告知游戏目标：新手教程的目标是让玩家了解游戏，所以它必须时刻提醒游戏目标的存在。Zynga将游戏目标置于主界面顶端，使其便于玩家查看。

易学易懂的用户界面

许多F2P游戏所依赖的机制来源于管理类或策略类游戏。这两种都不是简单的游戏类型，并且含有大量指令。用户界面不可让玩家反感，休闲游戏更是如此。以下是关于这个环节的一些关键设计技巧：

*主要控制方式应集中且清晰明了。要让玩家一眼就能看到界面有哪些选项。但主界面不可凌乱分布过多图标，只能在主界面范围内点击一个菜单选项，然后再出现一个子菜单。这样玩家就不会在游戏界面中失去方向感。

*菜单中的导航不可超过三个层次。在《CityVille》这款游戏中，提供最多选项的菜单是结构层，玩家只需要三个步骤就能完成操作：1）在主界面选择结构层菜单；2）选择建筑类型；3）选中一个建筑。

*每个指令都能通过标签等方式作出解释。

短暂体验，长期回访

留存率这就是F2P游戏的独特之处，这类游戏设计旨在让玩家在数个月甚至数年时间内经常访问游戏，但每次仅体验一小段时间。它能够做到这一点的原因如下：

*创造玩家的受挫感，刺激他们购买可以持续体验游戏的道具；

*通过广告促使玩家每天登录游戏。广告是F2P游戏的一大营收来源，广告商则希望借游戏获得高曝光度。

*克服无聊感。F2P游戏通常带有重复性操作。

而实现上述目标的核心设计机制又是什么呢？

*开环机制。著名社交游戏咨询师Tadhg Kelly对这个术语的解释是，许多社交游戏都是根据我们想完成一些任务（闭环）的渴望而设计，这些游戏让玩家去完成大量的琐碎任务，例如种植和收割胡萝卜，建设楼房，搜集足够的资源以完成升级，为建筑“雇佣”足够数量的好友。

玩家永远不可能拥有足够完成任务的资源（游戏邦注：能量点数、金子、木料或石油等），虽然他们也许能免费获取资源，但却需要花时间完成任务，所以他们离开游戏时，就会记得自己还有些未完成的任务（开环）。

玩家最迫切的希望就是返回游戏中关闭那些开环。当然，他们关闭了一个开环，另一个开环又会出现。总之游戏任务永无止尽。设计精良的F2P游戏会产生无尽的任务，于是玩家就得时常登录游戏完成一些操作，但每次仅体验数分钟时间。

《Mobster》或《Mafia Wars》这类游戏存在多种开环机制。这里我们以《Mobster》为例，玩家在游戏中的角色是发展自己的黑帮事业。从玩家角度来看，游戏目标就是发展自己的角色，解琐新装备，提升角色排名情况。起点非常简单，那就是完成相关任务，或者袭击其他玩家以赢取可购买装备的金钱。

但是，这些装备会产生维护费用。玩家因此就得投资那些可带来固定租金收入的地产，而为了赢取足以购买地产的金钱，玩家又得接受更困难的任务挑战，这些任务又需要他拥有更昂贵的装备。玩家会逐步发现更多新功能，例如范围更广的任务、迷你游戏、更多装备和组建Faacebook好友黑帮。

但玩家很快就会发现开发商欲令其重返游戏的心机和布局——装备总会产生维护费用。于是玩家就得掌握大量资金以便装备持续发挥作用，他的地产所创造的收益足以支付这项费用，但地产收入又总会让其他玩家眼馋并偷袭他。当然，那些未支付维护费用的装备在此时就派不上用场，无法帮助玩家抵御外敌。

怎么解决这个问题呢？——获得更多可以抵御他人来袭的装备，而这些装备又会产生更多维护费用，迫使玩家保证其收益来源的安全，而玩家的财产又会招来更多窃贼！为此，玩家不得不因自己所获取的装备和等级，不断壮大角色的实力，同时又得时刻警惕自己的资产被贼惦记。

*限制玩家掌握的资源。为了执行游戏的主要操作，玩家必须投入一定的游戏资源：健康值、精力、食物等等。他们可以用这些资源去完成收割庄稼等可以盈利的操作。而游戏总会让玩家快速消耗这些资源，它们虽然会自然恢复，但速度却很缓慢。这时烦躁的玩家就会发现自己不得不再等上一段时间，才能继续执行之前的操作。这种机制在F2P游戏中极为常见，但MMO和动作类游戏例外。

*奖励定期回访的玩家。《Pet Society》设置了一个每日登录的抽奖系统，而《CityVille》则为每24小时内访问一次游戏的玩家提供一种会增值的礼物。

*强制性任务。一些F2P游戏会迫使玩家返回其中完成琐碎的任务。《Mafia Wars》的玩家每天都要点击自己的地产以便从中收租；《Smurfs’ Village》中的庄稼如果不及时收割就会枯萎。这种机制也许会让玩家极度不满，毕竟没有多少人喜欢受到束缚，但它却能够推动某些虚拟商品的销售（这些虚拟商品能够自动在特定时间内帮玩家处理一些琐事），关键就在于游戏任务需具有一个可取悦玩家的目标。

*新功能和特殊活动。F2P游戏并不处于停滞发展状态，经常会引入新功能（游戏邦注：包括新装备、新任务和特价活动）以维持玩家对游戏的兴趣。

*鼓励与好友行互动。F2P游戏的成功很大程度上归功于其强大的病毒传播特点。这类游戏需让玩家邀请好友入伙，让好友也来关注游戏进程。这种“病毒扩散性”具有双重功效，不但可以让玩家引进新人，而且还可以通过这些新用户提醒并促使玩家持续体验游戏。因此在许多F2P游戏中，玩家总会收到好友的求助信息，并向其伸以援手。这样玩家就会为了好友而玩游戏，不再是单单为了自己的进展重返游戏。

在设计中融入玩家邀请机制

这对任何一名F2P游戏开发者来说都是个不容忽视的问题。只有5%至10%的注册用户会花钱消费。如果我们想扩大收益，首先就要拥有足够的用户规模。那么，怎样获得大量用户呢？

针对社交平台开发游戏。最直接的途径就是将游戏与社交平台绑定，这样游戏就很容易访问玩家的好友列表。拥有8亿用户以及2亿多玩家的Facebook当然是首选，但开发者还有其他选择，例如：

*专门的PC游戏门户网站，例如Bigpoint、Gaia或者Playfirst。虽然这些公司的游戏社区并不能与Facebook相提并论，但其用户均属于纯粹的游戏玩家。Bigpoint游戏玩家已经超过2亿，并且数量有增无减。这些平台都在与外部开发商进行合作。

*智能手机社交平台。苹果已经推出了自己的Game Center，虽然它本质上还不能算是一个社交网站，但无论玩家的好友是否属于Game Center注册用户，它都可以向其传递你正在玩的游戏等信息。因此，Game Center是一个让游戏通过“病毒式传播”并获取新玩家的好工具。此外，还有一些第三方手机社交平台可供选择，例如OpenFeint、Mobage、木瓜移动等。

*Google+。很显然，谷歌有意与Facebook在游戏领域展开角逐。这个谷歌平台的优势包括Gmail和好友列表等功能。

*Xbox Lve和PSN。这两者本质上就属于社交平台，但它们直到最近才开始向F2P游戏打开门户。微软和索尼不久前才宣布F2P游戏将登陆这两个平台。微软尤其重视其游戏服务的发展，正致力于将游戏与Windows、Live Messenger以及Xbox Live社区绑定。

但绑定社交平台也并非唯一的门路，许多F2P游戏就属于独立的网页游戏，这并不妨碍它们获得成功，例如Nexon的《Combat Arms》、Riot的《英雄联盟》，不过通过这种路径获取大量用户更为困难。

创新。全新的游戏理念更易受到关注。强大的品牌授权当然可以提高曝光度，但却无从告知其游戏体验有何新意。在F2P游戏领域还有许多新题材和新玩法尚待挖掘。

多人游戏玩法。对于那些没有入驻社交平台的游戏来说，驱使玩家邀请好友加入游戏无疑是一个大胆的选择。换句话说，这类游戏没有单人模式，《英雄联盟》走的正是这种路线，它提供的是团队作战的玩法。你当然可以一直跟陌生人玩游戏，但跟好友一起体验游戏更有趣和高效率。因此，这种游戏理念更易激发你和好友之间的团结感。

交叉营销推广。另一个吸引新玩家的有效途径就是交叉推广，即通过X游戏向玩家展示Y游戏条幅广告。这对那种已发布多款游戏的公司来说不失为一种理想选择，但如果你只有一款游戏怎么办？不妨试试Applifier这种支持小型开发商结盟，交叉推广彼此游戏的解决方案。

瞄准玩家的文件目录。单独运营的游戏另一个选择就是，请求玩家允许游戏访问其Messenger或Yahoo!好友列表，并通过电子邮件向好友发送邀请信息。

根据反馈参数设计游戏

Ben Cousins（游戏邦注：他之前是EA旗下的F2P游戏工作室Easy Studios总经理，最近已加入Ngmoco团队）曾表示，他们致力于变身为基于数据的工作室，而不仅仅是靠创意生存的团队。F2P游戏的成功离不开有效的用户数据，因为后者可以指导开发团队的工作，告知他们应如何更新内容。

记住F2P游戏通常不会以“成品”形式发布，这就为开发团队留下了新的发展空间，他们可以根据用户期望创造新内容，而无需在用户并不待见的内容上浪费功夫。用户数据还可以传达玩家如何操作游戏等信息。以下是分析有用数据的一些例子：

*玩家开始“退出”的游戏发展环节；

*最易带来玩家每日回访量的开环内容；

*促使玩家首次采取消费行动的因素；

*每名玩家平均消费情况；

*调整道具售价对游戏总营收的影响；

*不同玩家群体的盈利性。例如，哪些玩家为游戏带来最多收益，是一小部分资深玩家还是大量的普通玩家？

开发者需重视搜集这些数据类型，并且在游戏发布之前就布置好搜集数据的工具。不可在游戏上线后才草率追加这种设置，应该一开始就确定好自己的需求，清楚自己想知道玩家在游戏中的哪些情况。这样可以避免搜集到大量无用数据。

确定好要搜集的数据类型后，就要设计分析数据的方法，例如是用表格还是图表方式呈现？需要知道平均情况，还是总体趋势即可？如果数据很容易分析，那么你就需要经常分析并适应新情况，要知道数据信息很容易过时。最后要牢记的是，数据并不能取代创意设计。良好的反馈参数系统只能指出存在问题或发展机遇，但实际上并不会教你怎么做！（本文为游戏邦/gamerboom.com编译，拒绝任何不保留版权的转载，如需转载请联系：游戏邦）

The Design of Free-To-Play Games: Part 1

by Pascal Luban

When we talk about free-to-play games, we are not talking of a new genre, but instead of a deep revolution that is affecting most aspects and actors of the game industry: marketing, publishing, hardware manufacturers, and of course, designers and developers. Free-to-play (F2P) is here to stay. That is good news; it is expanding the number of people who play games, it is stimulating the industry after a slow-down, and it gives us the opportunity to create new gaming experiences forplayers.

A free-to-play game does not require its full content to be created before its release, as most content is created gradually after the game launch. Thus Nexon estimates that a free-to-play can be released with only 50 percent of its final content, and for Playfish, the percentage is as low as 20 percent!

AD – Autodesk

There are other reasons which explain the low initial investment: the technologies used are often simple and inexpensive. Also, because the game is free, players are not as demanding.

Lastly, most users are casual gamers with lower expectations than seasoned gamers. However, the cost of F2P games is likely to rise, especially for those that aim at core gamers. League of Legends offers the same production values as a retail game.

One of the secrets of success of a F2P game is the implementation of a powerful system of statistical analysis. Game data provides clues as to the users’ behavior and preferences.

By using this data and by carefully listening to the players’ remarks, developers can correct the flaws and build upon the strong points of the game. If the high concept of a game is good, the risk of game failure due to a perfectible development is eliminated, a major problem plaguing traditional game development.

But enough of an overview: let’s talk key design issues. One could argue that the design of a social game like FarmVille has little in common with Combat Arms or League of Legends, two F2P games targeting the hardcore crowd. However, no matter what genre, nearly all F2P are following the same specific design rules. Those are the ones I will describe now.

The Key Design Differences between Traditional and Free-to-Play Games

To begin with, let’s see why designing a F2P game is so different from a game relying on traditional business models.

In a traditional game, the designer’s only concern is to entertain the player, whereas in a F2P game, the focus is both on the player’s entertainment and his monetization. This quote from Jamie Cheng, the founder of Klei Entertainment, best illustrates this difference: “Don’t make people pay for entertainment. Entertain them so that they will pay.”

What are the new design objectives that a game designer working on a F2P game must keep in mind at all times?

Provide immediate satisfaction. The fact that a F2P game is free removes a major obstacle to experiment with a game: the price. However, it creates a new challenge instead: how to persuade a player to continue playing an F2P game when it’s so easy to switch to another if the current one doesn’t prove satisfactory.

When players purchase a game, they bind themselves to it. They have invested money in this game, and will not abandon it a few minutes later if their first impression is disappointing. It’s only several hours later that they will choose to drop the game if they don’t enjoy their experience.

However, if a game is free, this “bonding” doesn’t exist anymore. If the game, which didn’t cost them a dime, doesn’t bring immediate satisfaction, they will abandon it and switch to something else. Therefore, the first design challenge is to provide immediate satisfaction to the players in order to “hook” them.

Design for a (very) long duration of play. In F2P games, the longer someone plays a game, the higher the chances he will purchase items. Designing a game that will keep players active for months is a challenge we are no longer used to. Apart from MMOs and multiplayer games, the design trend during the last few years has been to provide players with intense but brief game experiences. Therefore, we must learn once again to develop long-lasting games. The design objective is to get players to play often, for brief periods of time and for months.

Design for new audiences. While certain F2P games such as MMOs or FPSs belong to known genres, many F2P titles address a broader one, with more women or younger players — and both may not be used to playing traditional video games. Their motivations to play are different, and so are their expectations. “Older” players — i.e folks beyond 30 years old — usually have a family and a busy life. For them, game sessions have to be short. And women will see the game as a support for interpersonal relationships, not a tool to compete. Define your target audience; know its gaming habits and expectations.

The Key Design Principles For a Good F2p Game

Immediate Accessibility

New players are precious. When one has expressed his intention to experiment with your game, you don’t want to lose him for any reason before he is hooked.

The game should be launched as directly as possible. The more steps a player has to follow to launch the game, the higher the chances of losing him. This is one of the reasons why Facebook games are so successful. There’s no need to register, to download or to install any application. To enter the game, the player only has to click a link.

To illustrate the negative impact of any extra steps required from the player, I will take the Unity 3D example. Unity has developed a great plug-in for Facebook.

Its installation is as simple as possible; it is a one-click installation, it is very fast and the user is not bugged with ads. Unity has honed the installation process so carefully because, in the past, 40 percent of players launching a game didn’t complete the installation, CEO David Helgason wrote in 2008.

Of course, this ratio varies, depending on the content. Great applications feature much higher installation rates. The point is that many PC users are simply reluctant to install anything. Now imagine what happens if they are asked to enter their details or download and install an application.

There are exceptions to this rule: Great F2P games like Maple Story or Combat Arms require a full registration and the download of a big client. However, these games were released under favorable circumstances: There was little competition.

There are two sets of solutions to this problem:

* Make the game available on an existing platform such as Facebook, or a portal like Bigpoint. Develop it in Flash or HTML5.

* Develop a game that runs in a web browser. Battlefield Heroes opted for that solution.

Take the player by the hand. There’s no better way to discourage a player than to “drop” her in a game he is not familiar with. Many F2P games guide the player’s first steps by forcing her to discover the basic actions and by limiting the access to advanced functions. This prevents players from getting lost amidst many unknown functions that will force them to make blind choices — having to choose among too many options is a source of anxiety for many casual or non-gamers. Easy access to a game also means easy use of its features.

Limiting the number of actions to take doesn’t make the game less attractive. More, complex actions are still available, but are only gradually revealed. The design objective is to propel the player in a virtuous spiral: 1) I understand what I have to do, 2) I perform the action easily, 3) I succeed in performing the action, 4) I receive a reward, 5) I discover a short term objective and I understand how to reach it. The player must not fail — this is an important condition to motivate her to continue discovering the game.

Two other design features are often found to support this teaching strategy:

* The use of a progress bar that gradually fills up while the player discovers new game functions in the order set by the tutorial. This simple bar makes players aware of the progress they make, which stirs their curiosity and motivates them to discover all the game features.

* Game objectives are put forward. Since one of their primary objectives is to teach the game, the player must always be reminded of their existence. Zynga makes them stand out by displaying them on top of the main screen.

Easy-to-Use and Easy-to-Understand Interface

Many F2P games rely on game mechanics derived from management or strategy games. Those are not simple genres, and feature lot of commands. The interface must not be a turn-off for players, especially casual ones. Here are the key design techniques used to facilitate the control of the game:

* The main controls stand out and are centralized. The player can see what options are available in one glance. However, the main screen must not be cluttered with icons. A click on a menu item opens up a sub-menu but within the main screen. The player never loses touch with the reassuring gaming screen.

* Navigation within the menus tree never go beyond three layers. In CityVille, the menu offering the most options is the construction one, and it is made up of three steps only: 1) the selection of the construction menu in the main screen, 2) the selection of the building type and 3) the selection of a building.

* Explanations for each command are always available, usually through a roll-over or a label.

Play a Little at a Time, But Return For a Long Time

This is called retention, and is a distinctive feature of F2P games: those games are designed to be played little at a time but very often, during several months or even years if possible. Why? There are several reasons:

* To create frustration in the player, and to stimulate him to purchase the items that would let him continue playing the game.

* To motivate the player to log in every day. Advertising is a revenue source for F2Ps, and advertisers are looking for high exposure.

* To fight boredom. F2P games often entail repetitive actions.

Which are the key design mechanisms used to that end?

* The open loop. Tadhg Kelly, a brilliant social game consultant, explains that many social games are built around our innate desire to complete tasks, to close loops. Those games are offering the player to complete lots of small tasks: to plant carrots and harvest them, to complete a construction, to gather enough resources to finish off an upgrade, to “hire” enough friends to staff a building, etc.

The player never has enough resources — energy points, gold, lumber, oil, etc. — to complete them. Those are free to acquire, but they need time to build up, so the player, when she logs off her game, knows that she leaves behind uncompleted tasks, open loops.

Her dearest desire becomes to return to the game to close the open loops. And, of course, as soon as a loop is closed, another one is created. It is a never- ending story. Well-designed F2Ps generate endless number of tasks. The result is that the player logs in the game very often, but only plays a few minutes at a time.

A variation of the open loop mechanism can be found in Mobster or Mafia Wars. Let’s use Mobster as our example. The player’s role is to manage the career of a gangster wannabe. From the player’s perspective, the purpose of the game is a classical one: to develop his character, to unlock new equipment and to make it climb in the ranking. The starting point is quite simple: the player may fulfill missions or attack other players to earn money that he uses to buy equipment.

However, equipment generates maintenance costs. The player must therefore invest in properties that will provide regular rental income. In order to earn enough money and pay for lucrative properties, the player must undertake increasingly difficult missions that require more expensive equipment and so on. The player progressively discovers new features: an increasingly wide range of missions, mini-games, more equipment, and the need to form a gang made up of his Facebook friends.

However, the player soon discovers the devilish mechanism set up by developers to make him come back: the equipment generates expenses for maintenance. He needs lots of cash to keep them running. His properties generate revenues to do that but this money attracts other player who will attack in his absence. Of course, equipment whose maintenance cost is not covered cannot be used for protection.

The solution? To acquire even more equipment for better protection, which will generate even more expenses, driving the player to secure revenue, which will attract even more thieves! Thus, the player has develop a character, based on the equipment acquired and the level attained, but which he must permanently defend.

* The limitation of the player’s resources. In order to perform the key actions offered by the game, the player must spend game resources: health, stamina, food, movement points, whatever. Those resources are used to do gratifying actions like harvesting a field, an action that generates revenue. The trick is that they exhaust pretty quickly. They renew naturally, but very slowly. Thus the player will find himself in the frustrating situation of having to wait a while before resuming a gratifying activity. This mechanism is quite common in F2P games. The main exceptions are MMOs and action games.

* Reward to players who log in regularly. Pet Society offers a lottery that can be used once a day. In CityVille, the player earns a gift of increasing value if he logs in every 24 hours.

* Mandatory tasks. As with popular ’90s toy Tamagotchi, certain F2P games force the player to return to the application in order to complete chores. Thus, in Mafia Wars, the player must check his properties on a daily basis to collect the rent. In Smurfs’ Village, crops will die if not harvested on time. This mechanism may become frustrating for the player, since no one likes constraints, but it fully justifies the sale of items that will automate the chores during a given period of time. The key to success is to give the task a gratifying objective.

* New features and special events. F2P games are not static. New features are introduced in order to maintain the player’s interest: new equipment, new missions, and exceptional sales (a F2P boutique is managed like a store with promotions, events, etc.)

* Interactions with friends. The success of F2P games relies on their strong viral dimension. The game must encourage the player to draw his friends’ attention by inviting them to join him. But this “virality” has a two-way function. Not only are friends invited to play the game, but it is them who remind the player later and motivate him to continue playing. Thus, with many F2P games, a player is frequently reminded to ask for “virtual” help from his friends and give them a helping hand.

As a result, the user no longer plays for his progress but for someone else’s.

Embedding the Player Recruitment in the Design

This is the key issue for any F2P developer. Only five to 10 percent of the registered users make any purchases. If we want to generate revenues, having a large community of players is essential. How can we generate a large number of players?

Develop for a social platform. The most obvious path is to integrate the game in a social platform where you can have easy access to the player’s friends list.

Facebook is the one that comes up first, with its 700+ million members and 200 million players, but there are alternatives:

Game Advertising Online

* Dedicated game portals on PC, such as Bigpoint, Gaia, or Playfirst. Their communities are not as large as Facebook’s, but they offer the big advantage of being essentially made up of gamers. Bigpoint already features over 200 million gamers, and the figure is growing. All of them offer partnership deals to external developers.

* Smartphone game social networks. Apple already has its Game Center. Part of the IPhone software suite, Game Center is not really a social platform, but it makes it very easy to tell your friends, whether they are already registered in the Game Center or not, about the game you are playing. Therefore, it is a good tool to “viralize” your game and get news players. There are also third party offerings, such as OpenFeint, Mobage, and Papaya.

* Google+. There is little doubt Google wants to compete head on with Facebook on games. Google can boast a great asset: Gmail and its friends’ list.

* Xbox Live and PSN. Those environments are natural social platforms but they were closed to F2P games… until now. Microsoft and Sony have very recently announced that free-to-play games will appear on their networks. In particular, Microsoft is working hard at integrating Games for Windows, Live Messenger, and the Xbox Live community in one seamless environment.

Integration into a social platform is not the only way to make it. Many F2P are stand-alone browser games. They can be quite successful, as Nexon’s Combat Arms or Riot’s League of Legends, but the road to building a big audience is much, much tougher here.

Innovate! A new game concept is a natural way to create buzz. The varnish of a strong license will get people’s attention, but they are unlikely to tell their friends if the game experience brings nothing new. And there is still a lot of room for new game themes and new gameplay mixes in the realm of F2P.

Design for co-op gameplay. For games with no connection to a social platform, a daring choice is to force the player to invite friends in order to play the game. In others words, there is no one-player game mode. This is the choice made by League of Legends, which offers team-based gameplay. You can always play with strangers but it is way more fun, and effective, to play with pals. Therefore, the game concept gives you a very strong incentive to rally your friends.

Cross-marketing. Another effective way to attract new players is cross-marketing. A user playing game X will see a banner while playing his game suggesting him or her to play game Y. This very effective tool is perfect for companies publishing several titles but what if you have only one? Applications like Applifier allow smaller developers to band together and cross-promote their titles.

Tap into the players’ directories. Another option for stand-alone games is to ask the player to grant you access to his or her Messenger or Yahoo! friends list, and send invitations through email.

Planning for the Metrics

Ben Cousins, who was until recently general manager of Easy Studios, an EA studio focusing on F2Ps — he has since gone to Ngmoco — stated that they learnt to be become a data-driven studio, not just a creative-driven one. User data is very important to the success of a F2P game, because it is the tool that tells the team how to steer the development of their game, and how to renew its content.

Remember that a F2P is rarely launched with its full content. This allows the dev team to develop the content players want to see, and not waste time on content they don’t like. User data can also provide key information on how players are using the game. Here are a few examples of the key learnings one can obtain by analyzing the correct data:

* The moment in the game progression when players tend to “drop out”

* The parameters in the open loop that are the most effective at generating daily visits

* The factors that drive the first purchase

* The average amount of individual purchases

* The impact on revenue of a item price modification

* The revenue generated by the different player profiles. In other words, who is generating the most revenue, the few heavy users of the game, or the numerous casual users?

The type of data to be collected and the tools to exploit them must be defined well before the game is launched. They should not come as an afterthought. Define your needs first. Begin to identify what you want to know about the ways your users are playing the game. This will prevent you from asking for tons of data nobody will use.

As you define the data you need, design the way you want to analyze them: will a chart or a graph be more effective? Do you need averages only or do you need trends?

If data are easy to analyze, you’ll do it more often and be more responsive. Keep in mind that data age quickly. Last but not least, data does not replace creative design. Good metrics will point to problems or opportunities, but will not tell you what to do about them!（source: gamasutra）