Game Design From Concepts To Implementation Games Go Mobile
The Future of Gaming is Mobile! As computer games become increasingly persistent, there will be an increasing demand to access the game information at all times. Guido Henkel (Game Over Magazine, 2004)
Mobile Does NOT Mean Phone First of all, because there are a number of portable gaming consoles which are not phones They are greatly outnumbered, but nevertheless they are there Secondly, playing on the move implies player s mobility, not just software mobility
Why Mobile is so Important? Think about ubiquitous computing Computer power everywhere, at every time, no matter what Think about ubiquitous network access Data access everywhere, at every time, no matter what What is so wrong in playing everywhere, at every time, no matter what? With a decent (ubiquitous) computing With a decent (ubiquitous) network access
Pervasive Games Pervasive games extends gaming experiences into the real world They include locative games But we need something to help us, and moving with us What is this object in the modern age? A phone! This, is why you usually get confused
Location Based Games Players move into the real world while playing Their position and actions affect and are affected by events in the virtual world Many examples are available
Uncle Roy All Around You http://www.blasttheory.co.uk/bt/work_uncleroy.html Uncle Roy All Around You is an urban game by Blast Theory from 2003 Street Players use handheld computers to search for Uncle Roy, using the map and incoming messages to move through the city Online Players cruise through a virtual map of the same area, searching for Street Players to help them find a secret destination Using web cams, audio and text messages players must work together to find Uncle Roy
Metal Gear Solid: Portable Ops http://www.konami.jp/gs/game/mpo/ 2006 portable edition of the award-winning franchise It is possible to enlarge a player platoon picking up soldiers by "war driving" around. Grabbing signals from places like fast food restaurants, bridge toll plazas and other locations that use wireless signals Random character generation will use GPS information and surrounding WiFi information
Augmented Reality Games Overlaying computer information onto the real world Augmented Reality is the overlaying of computer generated information onto the real world
ARQuake http://wearables.unisa.edu.au/projects/arquake/ ARQuake is an Augmented Reality version of the popular Quake game Unlike a Virtual Reality (VR) world, where the viewer sees a completely synthetic (virtual) environment, users immersed in an AR environment can still see the real world
Back to Heart When developing market-level games, what we care about is games running ON mobile (phones)
Some Challenges From the Market Multiple operating systems Palm Windows Symbian SONY ETI RIM ios Linux (moko) Android
And Challenges from Manufacturers Multiple devices from the same manufacturer (with very different capabilities) Treo s Blackberries Nokia
And Challenges From the Users Users have a phone, but may want to use something different Cheaper Faster More supported Trendy
Bottomline It is a mess! No device has all the features needed to do everything Phones serve the ear Tablets serve the eye Portable consoles serve the thumbs
Then, Why Focusing on Phones? Let s put this in term of device usage Tablets are an adults-only device Game handhelds are a children-only device Phones are an EVERYBODY device Therefore, phones will have the broadest range of game types
The Real Change for Us We can assume that the player is ALWAYS connected But we must be ready to pay a price for that The device will suffer from a number of constraints Limited resources Limited screen and interaction Touch gave a huge help Limited options for development Sharing the device with a number of other (seemingly useful) applications Like an agenda and a calling system
Know When Player are Playing Adults: during brief breaks, or while commuting This suggests short, simple games Children: whenever they have free time. Children s games can be bigger than adult ones! Games that depend on location or travel? Useful in theme parks Fun for tourists
Localize the Fun People want their native forms of entertainment Whatever entertainment means to them We should learn to build games based on culture Can t sell Western products at Western prices Mobile phone gaming is set to go big in India because the hardware is already there, and in huge quantity This may be a problem if you have a single price worldwide (itune store/android market)
Forget About Local distribution If we have to do something, it must worldwide Global market are accessible even for indie How many few bucks do you have to get in order to break even? Hundreds! The (single) blockbuster productions Either you time is free, or you have to produce tents of small games, and hope for one to cover the expenses for all of them
Distribution, from a Designer s Point of View Delivery cost is a function of size, no need to fit it into a CD/DVD A game can be as large as it needs to be We can assume the player is on-line and make use of that
Games are not Movies Movies can sell the same content many times Spectator will pay again to see multiple time Gamers will pay once to play forever and on many media Cinema, pay-per-view cable, pay cable channel, free cable channel, broadcast, VCR/DVD Digital delivery is only one Movies are not tied to a display technology Games are connected to a console/phone You can still watch movies that are 50 years old You need an emulator for games, but then, they are abandonware Movies have star power People feel a personal attraction to movie stars Mario, Zelda, Snake others are 2/3 shots
Human-Related Issues Not for us to Solve How important is the retail shopping experience? Retailers may actually add some value Maybe people like browsing in game shops Like in book shops Some sales are impulse purchases Children whining in shops makes games sell Is it important to get a box at Christmas? Maybe your [girl/boy]friend will not like an URL in an envelope
Game Networking Approaches We have two possible ways to implement it: 1. Server centric Server-driven games Client-server service model Cross carrier Cross platform IP based 2. User centric Peer-to-peer games Ad-hoc network service approach No Carrier (and no billing) Bluetooth based (WiFi used rarely)
Server Centric Approach All data traffic is routed through the operator The bill is a player s issue Each phone communicates only with the remote server Connection drop must be managed Server is responsible to tracks all player s actions and to send each player the games state It is also a single point of failure Cellular network games are usually server-driven And usually provided by the operator itself
Advantages Only the server needs to know the whole game state More control, but again, a single point of failure Each phone sends and receives only the data it needs No sniffing, cheating is reduced this way With a fast server (or a farm), it is possible to scale up and run Massively Multi-player Mobile Games The problem, then, is to create a MMMG game; which is yet to come
Disadvantages Server costs are a pain! Hardware Software Hosting Infrastructure maintenance Bandwidth Customer support How much are we going to squeeze from the players?
Infrastructure Backend Developing multiplayer games is actually a double project Server side Usually a web-based service on a powerful machine Computational intensive Client side An highly customized client on a small device I/O intensive All is different Technologies Platform Testing It may double (or more) the project cost
User Centric Approach No participant is authoritative We need some election mechanism to select a coordinator Each device sends and receives data to/from surrounding device Area of coverage may become a problem Network partitioning Fading Each device keeps track of the overall game state Keeping synch is a problem Cheating is easy Bluetooth is a favorite Easy to setup as peer-to-peer Encryption on the socket; sniffing and cheating is more difficult Uses less energy than WiFi
Advantages Players supply both hardware and bandwidth Given that BT is free to use Much cheaper to play
Disadvantages Data flooding Poor scalability with the number of players Cheating is easy Sniffing Eavesdropping Impersonation Especially in WiFi (but BT has lower bandwidth) BT limits the connection to eight players at a time Not much of a MMOG, isn t it?
Which Kind of Network Service Do We Need? This strictly depends on the game Given the activity in the game Which are the required deadline? Are they strict or not? Actually, this may be the wrong question Rather, the game we design should depend on network availability
Server Centric Real-time is technically possible but may lead to bad side effect The game is bad because (the network) is not responsive Deadlines should stay anyway in order of seconds Turn based is much better RPG may have a future here Lost move for timeout in order of tens of seconds is acceptable on both sides Delay tolerant games are best suited Chess Go
User Centric Real time is possible Performance bottleneck come from driver implementation Deadlines may be set to tens of milliseconds WiFi is best, but uses more energy Bluetooth is preferable, but not all applications are compatible and support peering with other active devices Gaming requires proximity Round-trip-delay is bounded and depends by technology Deadlines should not be less than that Interference may play a role Never assume deadlines is linked only on access technology