SE320: Introduction to Computer Games

SE320: Introduction to Computer Games Week 7: Core Mechanics GazihanAlankus

Outline • Brief chat about projects • Core mechanics

Brief Chat about Projects • How is it going? • Four weeks left for your first presentation (December 13). What I expect: • A simple but playable version of your game • An in-class demo • (Optional) User tests (what you learned, etc.) • Meetings that you want me in • Help session

Outline • Brief chat about projects • Core mechanics

Today’s Lecture is Different • We will learn about elements of core mechanics • We will identify them in your game ideas • I expect you to think and participate

Core Mechanics • Space • Objects, attributes and states • Actions • Rules and Goals • Skill • Chance Rethink your game idea with these in mind Keep these in mind while improving your game [Jesse Schell, The Art of Game Design]

Core Mechanics • Space • Objects, attributes and states • Actions • Rules and Goals • Skill • Chance

Space • Where things exist • Discrete vs. continuous • Dimensions (2D, 3D) • Bounded areas, connected or not • Nested spaces

Questions: Space • Is the space discrete or continuous? • How many dimensions? • What are the boundaries? • Are there sub-spaces? • Are there multiple ways of modeling your game’s space?

Objects, Attributes and States Attribute Value Object Attribute Value Attribute Value

Example Object Attribute Value Position (100, 200) Ghost in Pac-Man Objective Avoid Pac-Man (state machine) Direction left Secrets?

Questions: Objects, Attributes and States • What are the objects in the game? • What are their attributes? • What are the possible states for each attribute? • How do attributes change state? • Any secret attributes?

Actions • What can players do? • “Verbs” of game mechanics • Operative actions • Move a checker forwards • Resultant actions (more strategic actions) • Force the opponent to make an unwanted move

Actions: Emergent Gameplay • Interesting resultant actions that emerge out of users’ behaviors • Identify them, nurture them • Tips to support this • Add more verbs • Make verbs act on many objects • Goals can be achieved more than one way • Multiple avatars • Actions that change constraints

Questions: Actions • What are the actions? • Which ones are operative? • Which ones are resultant? • What objects do they act on? • How many ways can players achieve their goals? • Can users change constraints? • What resultant actions do you want to see? • Are you happy with resultant/operative ratio? • What actions do players wish they could do? • Can you enable them as operative or resultant?

Rules • Tie together • Space • Objects • Actions • Consequences of actions • Constraints on actions • Goals • You can’t just tell them to do something unless you set up the rules to favor it

Parlett’s Rule Analysis

Goals • Concrete, understandable • Achievable • Rewarding • Short-term • Long-term • Series of goals

Questions: Rules and Goals • What are the foundational rules? • What are the related operational rules? • Are there different modes for rules? • What is the ultimate goal? • Is it clear? • Are different goals related to each other in a meaningful way?

Skill • Users’ levels of ability • Categories • Physical skills • DDR, guitar hero • Mental skills • Puzzles • Social skills • Most multiplayer games

Skill • Balance difficulty and skill for best experience

Questions: Skill • What skills does my game require from user? • Are there categories of skill that I’m missing? • Which skills are dominant? • Are these skills creating the experience that I want? • Does the game demand the right level of skill?

Chance • Things happening randomly in the game • Uncertainty -> Surprises -> Good! • java.util.Random.nextDouble() may not be enough Uniform Gaussian

Chance Random seed Always different values Fixed seed Same sequence of values

Getting Chance Right is Tricky • Calculate probabilities • Make sure undesirable edge cases do not happen

Risk Taking • Expected probability vs. trust in own skill • Example • Monsters appear randomly • What are the odds of me killing a monster if one would find me in that room? • High? -> will risk going in • Low? -> will not risk

Questions: Chance • What in your game is truly random? • What parts just feel random? • Does randomness give • Positive feelings (excitement and challenge) • Negative feelings (hopelessness and lack of control) • Would changing my probability distribution curves improve my game? • Do players have a chance to take interesting risks in the game?

Core Mechanics • Space • Objects, attributes and states • Actions • Rules and Goals • Skill • Chance • Rethink your game idea with these in mind • Ground your decisions with these • Later in your presentations inform us how they influenced your designs

SE320: Introduction to Computer Games