Level Up Your Code: Why Object-Oriented Programming (OOP) is the Backbone of Game Dev

Source: Dev.to

Introduction

If you’ve ever looked under the hood of a modern game engine like Unreal (C++) or Unity (C#), you’ll find one common denominator: Object‑Oriented Programming (OOP).
While functional and data‑oriented approaches are gaining traction, OOP remains the primary mental model for building complex, interactive worlds. In this post we’ll explore how the four pillars of OOP translate directly into game mechanics.

Encapsulation

In a game, an object (e.g., a player or an enemy) shouldn’t have its internal variables manipulated directly by every other script.
Encapsulation lets us hide an object’s internal state and expose only what’s necessary through methods.

Example – Player health

public class Player : MonoBehaviour
{
    private int health = 100;

    public void TakeDamage(int amount)
    {
        // Check for invincibility frames, armor buffs, etc.
        health = Mathf.Max(health - amount, 0);
        // Additional logic (e.g., death handling) goes here
    }

    public int GetHealth() => health;
}

An enemy script calls player.TakeDamage(damageAmount) instead of setting player.health = 0, preserving the player’s internal rules.

Inheritance

Why write the same code for a “Goblin,” an “Orc,” and a “Dragon” if they all share basic traits?
Inheritance lets us define a base class with shared properties and derive specialized classes from it.

Base class and subclasses

public class Enemy : MonoBehaviour
{
    public Vector3 Position;
    public int Health;
    public Transform Target;
}

public class ArcherEnemy : Enemy
{
    public float Range;
    // Additional archer‑specific behavior
}

public class BossEnemy : Enemy
{
    public void PhaseTwo()
    {
        // Boss‑specific phase transition logic
    }
}

This reduces duplication and centralizes common functionality.

Polymorphism

Polymorphism allows a single function to behave differently depending on the object that implements it.

Weapon example

public abstract class Weapon : MonoBehaviour
{
    public abstract void Fire();
}

public class Pistol : Weapon
{
    public override void Fire()
    {
        // Shoot a single raycast
    }
}

public class Shotgun : Weapon
{
    public override void Fire()
    {
        // Shoot five raycasts in a cone
    }
}

public class GrenadeLauncher : Weapon
{
    public override void Fire()
    {
        // Spawn a physics‑based projectile
    }
}

An Inventory script can call currentWeapon.Fire(); without knowing which concrete weapon it is.

Abstraction

Abstraction focuses on exposing only the essential features of an object. In game development we often use abstract classes or interfaces to define what an object does without specifying how it does it.

Interactable interface

public interface IInteractable
{
    void Interact();
}

Any object that implements IInteractable—whether a treasure chest, a door, or an NPC—can be interacted with using the same player code:

void TryInteract(IInteractable interactable)
{
    interactable.Interact();
}

OOP Pillars in Game Development

Conclusion

OOP isn’t just a set of rules; it’s a way to organize the chaos of a game world. By mastering these four pillars you move from “writing scripts” to “architecting systems,” making your games easier to debug, scale, and—most importantly—finish.

What’s your take? Do you prefer pure OOP for your games, or are you moving toward an Entity Component System (ECS)?