Why Requirements and game rules in LLD? - Purpose & Use Cases

The Big Idea

What if your game could avoid chaos and confusion from the very start?

The Scenario

Imagine trying to build a game without writing down what it should do or how players should interact. You start coding, but halfway through, you realize you forgot important details like how scoring works or what happens when a player wins.

The Problem

Without clear requirements and rules, development becomes chaotic. You waste time fixing mistakes, players get confused, and the game feels broken. It's like playing a game with no instructions--frustrating and unpredictable.

The Solution

Defining requirements and game rules upfront gives a clear roadmap. Everyone knows what to build and how the game should behave. This prevents confusion, saves time, and ensures a fun, fair experience for players.

Before vs After

✗ Before

start coding without plan
fix bugs as they appear
players complain about unclear rules

✓ After

write clear requirements
define game rules precisely
build game following the plan

What It Enables

Clear requirements and rules make building and playing games smooth, predictable, and enjoyable.

Real Life Example

Think of a board game like chess: its strict rules let players focus on strategy, not guessing how to play.

Key Takeaways

Without requirements, development is confusing and error-prone.

Game rules guide both developers and players for a better experience.

Clear planning saves time and creates fun, fair games.

Practice

1. What is the main purpose of requirements in game design?

easy

A. To describe what the game must do

B. To explain how players should play

C. To decide the game's graphics style

D. To set the game's price

Solution

1. Step 1: Understand the role of requirements

   Requirements define the features and functions the game must have to work properly.

2. Step 2: Differentiate from rules

   Rules tell players how to play, not what the game must do technically.

3. Final Answer:

   To describe what the game must do -> Option A

4. Quick Check:

   Requirements = what game must do [OK]

Hint: Requirements = what game must do, rules = how to play [OK]

Common Mistakes:

• Confusing requirements with rules
• Thinking requirements set player behavior
• Mixing technical needs with gameplay instructions

2. Which of the following is a correct way to write a game rule?

easy

A. The game must load in under 5 seconds

B. Players must collect 10 coins to win

C. Use a database to store player scores

D. The game engine should support 3D graphics

Solution

1. Step 1: Identify what a game rule is

   A game rule tells players what they must or must not do during play.

2. Step 2: Check each option

   Players must collect 10 coins to win is a player instruction (rule). Options B, C, D are technical requirements.

3. Final Answer:

   Players must collect 10 coins to win -> Option B

4. Quick Check:

   Rules = player instructions [OK]

Hint: Rules tell players what to do, not technical details [OK]

Common Mistakes:

• Confusing technical requirements with rules
• Writing rules as system features
• Ignoring player actions in rules

3. Given these statements, which one is a requirement rather than a rule?
1. Players can jump over obstacles.
2. The game must save progress automatically.
3. Players lose a life if they touch spikes.
4. The game ends after 3 levels.

medium

A. The game must save progress automatically

B. Players lose a life if they touch spikes

C. Players can jump over obstacles

D. The game ends after 3 levels

Solution

1. Step 1: Identify requirements vs rules

   Requirements describe system features; rules describe player actions and consequences.

2. Step 2: Analyze each statement

   Statement 2 is a system feature (requirement). Others describe player actions (rules).

3. Final Answer:

   The game must save progress automatically -> Option A

4. Quick Check:

   Requirement = system feature [OK]

Hint: Requirements = system features; rules = player actions [OK]

Common Mistakes:

• Mixing player actions with system features
• Choosing rules as requirements
• Ignoring automatic system behaviors

4. A game designer wrote this rule: Players must collect 5 coins to win. But players can win without coins. What is the likely problem?

medium

A. The game has too many levels

B. The requirement is missing

C. The rule is not enforced in the game logic

D. The game has a syntax error

Solution

1. Step 1: Understand the problem

   The rule says players must collect coins, but they can win without doing so.

2. Step 2: Identify cause

   This means the game logic does not enforce the rule properly.

3. Final Answer:

   The rule is not enforced in the game logic -> Option C

4. Quick Check:

   Rule enforcement = game logic implementation [OK]

Hint: If rule ignored, check game logic enforcement [OK]

Common Mistakes:

• Confusing missing requirement with rule enforcement
• Assuming syntax error causes rule failure
• Ignoring game logic role

5. You want to design a fair multiplayer game. Which combination best ensures fairness and fun?

hard

A. Flexible rules with no system requirements

B. Complex rules that confuse players and minimal system requirements

C. No rules but strict technical requirements

D. Clear rules for player actions and balanced requirements for system performance

Solution

1. Step 1: Define fairness and fun

   Fairness needs clear rules; fun needs smooth system performance (requirements).

2. Step 2: Evaluate options

   Clear rules for player actions and balanced requirements for system performance combines clear player rules and balanced system needs, ensuring fairness and fun.

3. Final Answer:

   Clear rules for player actions and balanced requirements for system performance -> Option D

4. Quick Check:

   Fairness + fun = clear rules + balanced requirements [OK]

Hint: Fair game = clear rules + balanced system needs [OK]

Common Mistakes:

• Choosing complex or missing rules
• Ignoring system performance impact
• Separating rules from requirements