Move validation in LLD - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is move validation in system design?

Move validation is the process of checking if a requested action or move in a system follows the defined rules and constraints before it is accepted and executed.

beginner

Why is move validation important in multiplayer games or distributed systems?

It ensures fairness and consistency by preventing illegal or cheating moves, and keeps the system state synchronized across all participants.

intermediate

Name two common approaches to implement move validation.

1. Server-side validation: The server checks every move before accepting it.<br>2. Client-side validation: The client checks moves before sending, often combined with server validation for security.

intermediate

What is a potential risk if move validation is only done on the client side?

Clients can be manipulated or hacked to send illegal moves, leading to cheating or corrupt system state.

advanced

How can move validation be optimized for scalability in large systems?

By using techniques like caching valid moves, partitioning validation logic, asynchronous validation with rollback, and minimizing validation complexity.

What is the main purpose of move validation?

A To store user data securely

B To speed up the system response time

C To check if a move follows system rules before execution

D To design the user interface

Move validation ensures that every move complies with the system's rules before it is accepted.

Which approach is more secure for move validation?

A Both client-side and server-side validation

B Server-side validation only

C No validation

D Client-side validation only

Combining client-side and server-side validation improves security and user experience.

What risk arises if move validation is skipped on the server?

A Cheating and inconsistent state

B More storage space

C Better user interface

D Faster processing

Without server validation, clients can send illegal moves causing cheating and inconsistent system state.

Which technique helps scale move validation in large systems?

A Validating only once per day

B Ignoring invalid moves

C Using only client validation

D Caching valid moves

Caching reduces repeated validation work, improving scalability.

Move validation is most similar to which real-life process?

A Buying groceries

B Checking a ticket before entering a concert

C Driving a car without a license

D Watching a movie

Just like checking a ticket ensures only valid entry, move validation ensures only valid moves proceed.

Explain what move validation is and why it is critical in distributed systems or multiplayer games.

Think about how a game server keeps the game fair and synchronized.

Describe common strategies to implement move validation and how to balance security with performance.

Consider how both client and server work together to validate moves efficiently.