Character Health and Score Management

Unreal Engine 5, C++

Why health lives on the character, not PlayerState

PlayerState is Unreal's usual answer for per-player data, but it earns its keep specifically in multiplayer — synchronizing things like score or kill count between server and clients. In a single-player game there's no synchronization problem to solve, so MaxHealth and Health just live directly on the character class instead. It's a deliberate short-term call, not a permanent one — if this ever needs multiplayer, PlayerState is the more scalable home for this data, but building that in now would be solving a problem that doesn't exist yet.

Damage and healing

Unreal's built-in damage system is two functions talking to each other: UGameplayStatics::ApplyDamage() is the call an attacker makes, and it internally tries to call AActor::TakeDamage() on the receiving end — a virtual function every actor already has, ready to be overridden.

UFUNCTION(BlueprintPure, Category = "Health")
float GetHealth() const;

UFUNCTION(BlueprintCallable, Category = "Health")
void AddHealth(float Amount);

protected:
UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Health")
float MaxHealth;

UPROPERTY(VisibleAnywhere, BlueprintReadWrite, Category = "Health")
float Health;

virtual float TakeDamage(
    float DamageAmount,
    struct FDamageEvent const& DamageEvent,
    AController* EventInstigator,  // who/what caused the damage
    AActor* DamageCauser           // the object that actually dealt it (a bullet, an explosion)
    ) override;

UFUNCTION(BlueprintCallable, Category = "Health")
virtual void OnDeath();

AddHealth() runs the recovered amount through FMath::Clamp so healing items can't push health past MaxHealth. TakeDamage()'s return value is the damage actually applied — usually identical to DamageAmount, but the hook is there for damage reduction or amplification if that's ever needed. OnDeath() fires once health crosses zero, and is the natural place for disabling input, switching to a ragdoll, or playing a death animation.

With that in place, the mine item's ActivateItem() from Picking Up Items on Collision calls UGameplayStatics::ApplyDamage() on whatever it caught in its blast radius, and the healing item calls AddHealth() directly — same character-side system, two different items driving it.

Score

Score works the same way conceptually as health, but lives a level up — on GameState, coordinated through GameMode — rather than on the character, since "current score" is really game-flow data rather than something intrinsic to the player character itself. Coin items call into that instead of tracking a score value on the character. The GameMode/GameState split itself is worth its own explanation — see Controlling Game Flow with a Game Loop.

Links

GitHub