Slide set rules

1
Designing Mobile Games
2
Speaker Introduction

• Name Greg Costikyan
• Organization NRC/Game House
• Location New York
• How am I involved in (mobile) gaming 3 decades
  as a game designer (30 titles published),
  co-founder of one of USs first mobile game
  developers, used to edit game section of Forum
  Nokia website, now work as a games resarcher for
  NRC.

3
What Does the Player Do?

• Game design is not about story or character.
• Game Design is about action.
• Not necessarily fast action, but the player takes
  actions to affect the game state.
• What does the player do?
• Media assets are the nouns of the
  gameallowable actions are the verbs
• UI allows you to trigger the verbs.
• Each verb mapped to a UI feature.
• In a mobile game, ideally 1 key 1 verb
• Possibly to net menus, etc., but preferable to
  keep actions mapped to individual key presses
• Write down your list of verbs.
• Possible to build a good game with limited verbs
  Doom has only 8 (left, right, ahead, back, jump,
  shoot, switch weapons, pick up)
• Can you see how your list could produce an
  interesting game?

4
Verbs (cont)

• Will a single key-press suffice?
• E.g., two used in golf games (direction and
  power).
• Avoid multiple simultaneous key-presses when
  possible, as many J2ME implementations dont
  permit this.
• If feasible, avoid mapping multiple actions to a
  single key, or different keys to the same action,
  to avoid player confusion.
• A single key to mean act or select can work,
  IF the meaning is always clear in context.
• Game design has two main components UI
  specification and gameplay algorithm
  specifications. The two must dovetail neatly, and
  it is worth thinking about clean UI design from
  the start.

5
Struggle Challenge

• A game should be a struggle.
• If too easy, it is boring.
• If too hard, it is frustrating.
• Have to find a happy medium.
• Players enjoy overcoming challenges.
• Difficulty settings help.
• Dynamic difficulty adjustment can be used, but
  carefully.
• Three basic kinds of challenges
• Physical
• Mental
• Opponents (AI or players)

6
Types of Challenges

• Physical Depends on timing and mastery of the
  interface.
• Mental
• Resource trade-offs
• Tricky placement of game objects
• Interacting systems whose behavior is hard to
  solve
• Combining game objects
• Even if your game is not puzzle-based, think
  about how to use the verbs of the game to produce
  interesting puzzles
• Opponents
• For multiplayer, this is provided by the other
  players
• In single-player, this is provided by AI.
• Even simple AI can make opposition more
  interesting to the player
• Example Space Invaders
• After defining verbs, defining the sorts of
  challenges your players will face comes next.

7
Categories of Pleasure

• Marc LeBlancs taxonomy of game aesthetics
• Always useful to think about what aesthetic
  pleasures players will draw from the game
• Sensation Graphics, sounds, tactile feeling,
  etc.
• Fantasy Consistent and appealing
  background/world/story.
• Can be simple An Italian plumber must rescue
  his girlfriend from a giant ape.
• Narrative Not necessarily story, but narrative
  arc Sense of heightening tension and release.
• Challenge.
• Fellowship Important particularly for
  multiplayer, but even with soloplay games,
  players enjoy talking about their experiences.
• Discovery Exploration, new things (with each
  level?)
• Masochism Submitting yourself to the structure
  of the game.
• Does your design provide each/some of these?

8
Constraints

• Constraints do not limit creativity they spur
  it.
• The sonnet.
• Application size.
• If targeting older Series 40 phones lt64k
• Application memory space
• When running, application consumes more than the
  app size itselfgraphic buffers, objects created
  at runtime, etc.
• For older Series 40 phones lt200k.
• Screen size format
• Characters should be 10-15 of height and width
  of screen
• If a HUD is used, it must be simpleideally lt6
  pieces of information.
• Portrait rather than landscape format.
• Processing power (complicated simulations a
  problem)

9
Constraints (cont)

• Mobile Device UI
• Can generally rely an an ITU-T keypad, two soft
  keys, D-pad
• No pointing device
• Variable keypads
• The social space of mobile devices
• Handle interruptions gracefully
• Go easy on the sound (and gameplay MUST NOT
  depend on it)
• Keep the backlight on
• High color contrast for readability in direct
  sunlight

10
How Multiplayer Games Differ

• Players provide the challenge
• Provide ways to help and hinder each other
• Replayability vital.
• Handle player drops gracefully
• Civil Disorder
• AI take-over
• Replacement player
• Or design so that the loss of a player is
  unimportant
• Player Matching
• Quick game.
• Challenges
• Reserving a game for friends (buddy lists?)
• Use of rankings to match players of equivalent
  skill
• Short play sessions
• Ideally lt15 minutes

11
Multiplayer Differences (cont)

• Balance no longer right difficulty level
• Instead all players have equal chance of
  winning
• However, asymmetric games can be balanced
• Diplomatic games are self-balancing
• Physical Depends on timing and mastery of the
  interface.

12
Game and Network Issues

• Server-driven games
• Ongoing cost for game provider
• Secure data storage
• Makes cheating harder
• Bandwidth-to-user not normally a constraint
• Peer-to-peer
• Cheaper for game provider
• Cheating easier
• With large numbers of players, bandwidth becomes
  a bottleneck
• Particularly for Bluetooth, which is always
  hub-spoke configuration
• Not feasible with legacy phones (requires IP
  address, SIP, or Bluetooth)
• Player matching/discovery becomes a problem

13
Dealing with Latency

• Always a problem with networks
• On wired Internet, 100-200ms latency rules out
  street fighters
• On 2G networks, 1 second latency
• If HTTP must be used, 5 second latency
• NRC tests show that UTMS can produce gt100ms
  latency
• ---But in lab, actual network deployments may be
  slower..
• And generically, 3G doesnt solve all
  problemsEV-DO in deployment 500ms latency
• In general, unless targetting UTMS, must always
  work around latency issues
• Approaches
• Turn-Based games (round robin or simultaneous
  movement)
• Act-whenever
• Slow update games
• Shared solitaire games
• Mask latency with game fantasy
• Untie game outcomes from specific play
  configuration

14
Designing for Community

• Shared high-scores, tournaments, etc.
• But many pitfalls
• Avoid incentives for player drops
• Dont encourage newbie-bashing
• No perfect scores
• Permanent high scores can be a deterrent
• Chat
• Keypad text entry a problemtaunts?
• SMS for persistent/long term games
• Pathway to Glory use of VoIP
• Friend Finding
• Buddy lists
• Phone number/User ID query
• SMS challenges
• Diplomacy
• Web presence

15
The Metagame

• Richard Garfield Magic The Gathering
• Anything surrounding the game that increases
  player interest
• Tournaments/seasons
• Trading
• Offline activities
• Stable strategies

16
No Single Methodology

• Tried to provide a coherent framework here
• This is an art, not an engineering discipline
• Kipling There are four and twenty ways/of
  writing tribal lays/And every single one of them
  is right.
• But in general, if you think about what the
  player does, what pleasures players draw from
  the game, and what techical and business
  constraints apply, youll start from a solid base.