Requirements and game rules in LLD - Architecture Diagram

System Overview - Requirements and game rules

This system manages the requirements and rules of a game. It ensures players understand the game objectives, allowed actions, and constraints. The system validates player moves and enforces rules to maintain fair play.

Architecture Diagram

User
  |
  v
Load Balancer
  |
  v
API Gateway
  |
  v
Cache
  |
  v
Game Rules Service <--> Rules Database
  |
  v
Response to User

Components

User

client

Player interacting with the game system

Load Balancer

load_balancer

Distributes incoming requests evenly to API Gateway instances

API Gateway

api_gateway

Entry point for client requests, routes to game rules service

Game Rules Service

service

Processes game requirements and rules, validates player actions

Rules Database

database

Stores game rules, requirements, and configurations

Cache

cache

Stores frequently accessed rules to reduce database load and improve response time

Response to User

response

Sends validation results and game rule information back to the player

Request Flow - 11 Hops

User → Load Balancer

Load Balancer → API Gateway

API Gateway → Cache

Cache → API Gateway

API Gateway → Game Rules Service

Game Rules Service → Rules Database

Rules Database → Game Rules Service

Game Rules Service → Cache

Game Rules Service → API Gateway

API Gateway → Load Balancer

Load Balancer → User

Failure Scenario

Component Fails:Rules Database

Impact:New or uncached rule queries fail, causing validation errors for uncached rules

Mitigation:Cache serves previously cached rules for reads; writes fail and trigger alerts for database recovery

Architecture Quiz - 3 Questions

Which component first checks if the game rules are already available to speed up the request?

A Rules Database

B Load Balancer

C Cache

D API Gateway

Design Principle

This architecture uses caching to reduce database load and improve response times for game rule validations. The API Gateway centralizes request routing, and the load balancer ensures even distribution of traffic. Failure handling relies on cache availability and alerts for database issues.

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