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Features

Developing Online Console Games
All
the major consoles - Playstation 2, Xbox and Gamecube - now support
online gaming. PC developers have been writing online titles for
years, but this is relatively uncharted territory for console developers.
Until recently, only a handful of multiplayer online games had been
created for consoles, and even fewer had been successful. The target
audience for consoles has different expectations from the PC market.
Console game designers are faced with limited input devices and
console manufacturer requirements that demand a different set of
design decisions. Console game developers are faced with adding
network programming expertise to their list of skills. And now console
producers have to schedule new online features and carefully consider
network skills in hiring decisions.
This
article examines the new world of multiplayer possibilities with
current-generation consoles, along with the limitations online console
game development presents. It contrasts the different approaches
the console makers have taken, and details the design and development
considerations involved in creating online console games.
Online
Strategies: The Big Picture
Each
console manufacturer is taking a different approach to enabling
online play. Microsoft is building an integrated service that emphasizes
a uniform experience across titles, while Sony and Nintendo are
investing less on back-end services and allowing more flexibility
across games. Each scheme has its benefits and drawbacks. Microsoft
requires that customers have a broadband connection, whereas Sony
and Nintendo are also supporting players with dial-up connections.
Xbox game designers have fatter pipes for game traffic, at the cost
of a smaller potential market. PS2 and Gamecube developers have
a larger potential market, but a wider range of bandwidths to support.
The next section examines each company's approach in detail.
PS2
Strategy
Sony
is the undisputed leader in terms of console market share. Sony
launched its first online game in Japan in May 2002 and in North
America in August 2002. Sony encourages PS2 game developers to support
both dial-up and broadband users, although some games have chosen
to support broadband only. For instance, SOCOM: U.S. Navy SEALs
is a broadband-only game. PS2 online players must purchase a separate
network adapter ($40), but there is no sign-up fee. Players can
use their pre-existing dial-up or broadband connection. Some games
support additional peripherals, such as a keyboard for online chat,
a voice headset, or hard drive. Sony encourages its developers to
provide multiplayer online gaming for free as an added feature,
although developers can charge a subscription fee for games such
as persistent-world games. For instance, the PS2 version of EverQuest
will charge a monthly fee.
From
a development standpoint, Sony provides an online API via the SCE-RT
library. This library is free to licensed PS2 developers. Sony is
building out facilities for hosting game servers, but they also
encourage developers to build and host their own services or use
third-party middleware and services. The advantage of this approach
is that the game developer has maximum flexibility. They can build
or buy, and they can manage their own customer base. A downside
of this flexibility is the inconsistency of online capabilities
and UI from title to title.
Sony
is allowing considerable latitude for online developers. For example,
developers can pick and choose how to implement multiplayer services
like matchmaking. The possibility exists of having cross-platform
compatibility with Gamecube or PC games. Buyers of online PS2 games
could conceivably find a large existing community of PC players
the very first time they log on. One potential disadvantage of this
open system is the lack of a global security infrastructure. As
online PC game developers have discovered, security is critical
to preventing cheaters from ruining the game experience. With many
different network library options available, there is a greater
possibility that any particular online title may have unsatisfactory
security built in.
Sony
has placed few requirements on online games. For instance, voice
is not a mandatory feature but rather left up to the developers
to decide if it's appropriate for a game. In general, the Sony strategy
is to maximize the potential audience for online games and give
game developers broad flexibility in choosing what features their
games should support and how those features should be implemented.
However, Sony is reportedly developing a more integrated service
for the European market called the Network Gaming Service (NGS),
with indications that it will support single player IDs and other
global features for titles that use the SCE-RT library. Whether
this indicates Sony is moving toward a more consolidated service
philosophy, at least in Europe, remains to be seen.
Gamecube
Strategy
Nintendo
is taking a cautious course, with the view that online gaming is
not yet a viable market. Nintendo launched its first online title
with Phantasy Star Online Episode I & II for Gamecube
in October 2002. Players must purchase a separate dial-up or broadband
adapter ($35) to play online. Like Sony, Nintendo is not charging
a sign-up or subscription fee. Online services must be built by
the game developer or accessed via third-party middleware.
Nintendo
has been characteristically tight-lipped about future online plans
for Gamecube. At the time of this writing, Nintendo does not appear
to be enforcing any types of policy decisions about voice communication,
keyboard chat, or global identities. There are also no indications
that Nintendo is committing large resources to back-end services
or other online infrastructure.
Xbox
Strategy
Microsoft's
online approach for Xbox is bold and hence, risky. Xbox itself was
designed with online play in mind; all consoles include a built-in
Ethernet port and hard disk. Microsoft launched its online service,
Xbox Live, in North America in November 2002, and it has announced
plans to launch in additional territories over the course of 2003.
To
use Xbox Live, players must have broadband, typically via a cable
or DSL modem using any ISP. Microsoft chose not to support dial-up
connections, limiting their market significantly. In addition, unlike
Sony and apparently Nintendo, Microsoft is charging players a fee
for the service. For $50 players get a one-year subscription, a
voice headset, and two games (MotoGP and Whacked in
North America). Games may charge additional fees if they wish, although
there are no current games doing so.
Microsoft
has built a suite of online services and online game APIs, some
of which are optional and some of which are required. From a development
standpoint, this is both a benefit and a limitation. The benefit
is that standard services like matchmaking are automatically available,
tested, and free to use. Developers don't need to roll their own,
pay for middleware, or pay to host their own matchmaking servers.
The disadvantage is that game developers may find themselves required
to use services that they normally wouldn't use or that aren't flexible
enough for their needs. Developers also need to budget additional
time for coding and testing required services. Currently, Microsoft
provides services for peer-to-peer matchmaking, buddy lists (including
online presence), game content delivery, voice chat, billing, and
persistent storage of player statistics. Developers may write their
own game servers if they wish, a necessity for massively multiplayer
games.
Unlike
Sony's (and presumably Nintendo's) relatively "open" approach,
Xbox Live is considered a "closed" service. Xbox Live
games cannot communicate with other consoles or with PC games, nor
can they access web sites or the Internet at large. Custom game
servers must be hosted in secure data centers approved by Microsoft.
A closed system is a disadvantage from the standpoint of the community-building
issue. It's hard to build community within such a limited environment.
The benefit of these restrictions is that games are heavily resistant
to cheating.
Microsoft's
online service also allows players to have a global identity across
all Xbox Live games. When players sign up for the service, they
choose a "Gamertag" that becomes their name in every Live
game. Gamertags are in turn used to build buddy lists (Friends lists,
in Xbox Live parlance), which are also consistent across games.
In addition, all Xbox Live games must support voice communication.
Microsoft is banking on voice becoming a key differentiator for
Xbox Live.
Microsoft's
strategy is to provide a consistent experience for players across
all Xbox Live games. Microsoft is investing heavily in its online
service, and it appears committed to the long-term success of online
play. Microsoft is providing a wide range of built-in technologies
and services to online game developers, but in turn requires developers
to make an engineering commitment to many global Live features.
Obviously, Microsoft is also making a calculated bet that the broadband
market will grow substantially in the coming years.
Online
Console Game Design Issues
It's
no secret that the typical console player is different from a typical
PC game player. How does this apply to game design issues for multiplayer
console games? The first difference is the couch versus back-room
mentality. When you ask PC game players how they most enjoy playing
games, their answer usually involves something about sitting at
the computer - by themselves - and beating the snot out of players
they don't know. When you ask console game players the same question,
their answer will typically include something about sitting on the
couch - with their friends alongside - and beating the snot out
of each other. Console players tend to play with their friends,
and they tend to play in a more social atmosphere.
The
second difference is that the average console player is less technically
knowledgeable and less forgiving than the average PC online gamer.
Console game players don't care about round-trip ping time, they
don't run traceroutes, they don't know an IP address from a P.O.
address, and they certainly don't want to configure routers. If
multiplayer gaming doesn't work for them, they will blame the game
- not their modem, not the ISP, and not the Internet. This means
that multiplayer gaming must appear to be an extension of single
player gaming. Techniques for doing this effectively include disguising
latency, avoiding unfamiliar terms like ping time, and not putting
players into sessions that don't have good bandwidth characteristics.
Consoles
are designed for the living room. They output to television screens,
not high-resolution monitors. They typically take input from controllers,
not keyboards or mice. Multiplayer console games must be designed
for the living room as well. Suggestions for online console game
designers include:
- Display
only the most critical information when showing sessions or player
information. Too much information clutters the screen and overwhelms
most players. Rather than packing data on the screen, prefer a
drill-down approach.
- Avoid
long lists; list traversal is difficult given limited screen resolution
and controller issues. If you have multiple pages of sessions
or players, provide a controller shortcut for getting to the next
and previous pages.
- Make
it easy for players to get into game sessions. Minimize multiplayer
configuration screens.
Writing
a game with voice communication presents additional design challenges.
First of all, it probably doesn't make sense, both from a bandwidth
and discernability standpoint, to allow every player to talk with
every other player during the game. That means that the game needs
to somehow limit players' use of voice. The most effective games
limit voice in ways that make sense to players in the context of
the game. Perhaps players can communicate only with their teammates,
or only with people near them in the game world. Or maybe the game
uses phones, radio channels, or other well-understood means of filtering
voice communication.
As
with online PC games, online console games must carefully budget
bandwidth and understand how to effectively tolerate latency. Even
with broadband-only games, broadband is not a panacea. All the lessons
PC network game developers have learned about disguising latency,
limiting network traffic, and handling dropped packets still apply
to broadband.
Topologies
Multiplayer
game topology is a key design decision that can have a huge impact
not only on gameplay but also on engineering time and long-term
costs. There are three general models to consider: peer-to-peer,
client-server where one console acts as the server, and client-server
when the server is external (Figure 1). These models are applicable
to PS2, Gamecube, and Xbox.
In
a peer-to-peer game, each console communicates with every other
console in the game. External servers are only peripherally involved,
perhaps during the matchmaking phase or for downloading new content.
The advantage of a peer-to-peer game is that no game servers need
to be designed, coded, or maintained. Peers communicate directly
without server involvement, so latency is minimized. The disadvantage
is that the number of peers is limited due to bandwidth constraints,
particularly with dial-up connections.
In
a client-server game where one console is the server, the console
could be either a dedicated server or an active participant in the
game. Like the peer-to-peer model, no external servers have to be
maintained. Unlike the peer-to-peer model, bandwidth becomes less
of an issue, since each console communicates only with the server
console. However, choosing the server console to maximize bandwidth
and minimize latency becomes important, as does handling host migration
when the server console shuts down or leaves the game.
A
client-server game with a custom external server typically provides
the ideal bandwidth characteristics, since the custom server can
reside in a high-bandwidth data center. However, this topology introduces
the most expense, both in terms of server development and testing,
as well as long-term maintenance, server management, and data center
bandwidth fees. Experienced server developers who also understand
gaming issues are rare.
Another
possibility is to mix and match topologies. In a massively multiplayer
game, for example, it may make sense to use the client-server model
for gameplay, but use a peer-to-peer model for voice communication.
The important thing is for developers not to confine their thinking
to any one model. Evaluate all the possibilities carefully.
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