VitalCore
Data-driven pawn vitals for single player and multiplayer

Overview

VitalCore replaces the usual hand-written "health float plus a few timers" with a complete, data-driven vitals system. Stats are defined in a data asset or inline on the component; effects are data assets; every value, timer and event is replicated from the server to all clients.

• Any number of named stats (Health, Stamina, Shield, Mana...) with current, maximum and minimum values.
• Regeneration per stat with a rate and a delay after damage or use.
• Damage resistances per damage type class plus a flat armor value.
• Shield that absorbs damage before health, with its own recharge delay and a break event.
• Timed effects: damage or heal over time, stat drain or boost, with tick interval and duration.
• Status effects with stacks, maximum stacks, refresh/extend policy and stat modifiers.
• Downed state with a bleed-out timer, death and revive with a health fraction.
• Invulnerability window after hits and revives, plus a god-mode toggle.
• Multiplayer: server-authoritative, replicated stats and effects, events on every machine.
• Engine damage hook: the engine's Apply Damage nodes work without extra code.
• Hit info: last hit direction and angle, instigator tracking, kill credit and assists.
• Fall damage from landing speed for characters, linear or curve based.
• Save / restore of every stat and effect into one struct for your SaveGame.
• Stamina spending with exhaustion lockout and a sprint drain helper.
• VitalCore.Debug on-screen display and a Blueprint function library.

Requirements

Installation

1. Install VitalCore from Fab into your engine, or copy the VitalCore folder into your project's Plugins folder.
2. Enable VitalCore in Edit > Plugins and restart the editor.
3. C++ only: add PublicDependencyModuleNames.Add("VitalCore"); to your Build.cs.

Quick start

1. Add the Vitals component to your character. It already has Health (100) and Stamina (100, +20/s after 1 s).
2. Make sure the actor can be damaged (Can Be Damaged is on by default).
3. From any weapon, call the engine's Apply Damage on the character. Health goes down; On Damaged fires on the server and on clients.
4. Bind On Death to play a ragdoll or respawn; call Reset Vitals on respawn.
5. In the console type VitalCore.Debug 1 to see every pawn's stats above its head.

1. Stats

Component UVitalCoreComponent — displayed as Vitals. Stats come from an optional Data Asset UVitalCoreProfile (Add > Miscellaneous > Data Asset > Vital Core Profile) and from the inline Stat Definitions array; an inline stat with the same name replaces the profile's.

Runtime values are struct FVitalCoreStat (Name, Current, Max, Min, Base Max, Regen Rate, Base Regen Rate, Regen Delay, Regen Resume Time). Nodes: pure Get Stat, Get Stat Value, Get Stat Max, Get Stat Percent, Has Stat, Get Stats, Get Health, Get Health Percent, Get Shield, Get Stamina; server Modify Stat, Set Stat Value, Set Stat Base Max (Keep Percent), Set Stat Regen, Add Stat, Reset Vitals.

2. Regeneration

Every stat with a non-zero Regen Rate changes by that amount per second on the server. Any decrease (damage, drain, spending, sprint) restarts the stat's Regen Delay; damage that only hit the shield still restarts the health delay, and hits on an empty shield keep the shield waiting. Regeneration stops on death; while downed only stats with Regen While Downed continue (never health). Stamina does not regenerate while sprinting.

pure Get Regen Delay Remaining (Stat) returns the seconds until a stat regenerates again — handy for a shield recharge indicator. Status effects can add to or multiply the regeneration (see Status effects).

3. Resistances & armor

Every hit is processed in this order: Damage = Incoming × Damage Multiplier − Armor, then the shield, then health.

pure Get Damage Multiplier (Damage Type) and Get Effective Armor return the values in use, including status effects. server Apply Vital Damage (Amount, Damage Type, Instigated By, Damage Causer, advanced: Hit Location, Direction, Bone Name) applies damage directly and returns the health lost.

4. Shield

When the owner has the stat named by Shield Stat, it absorbs damage before health. Its regeneration rate and recharge delay are those of its stat definition, so the shield recharges on its own timer.

event On Shield Broken fires when damage empties the shield (server and clients). FVitalCoreHitInfo reports the shield part of each hit in Shield Damage.

5. Timed effects

Data Asset UVitalCoreEffect — Add > Miscellaneous > Data Asset > Vital Core Effect.

Ticks due when the effect ends still run, so 5 s at 1 s interval ticks exactly 5 times. Timed damage never starts the invulnerability window. Without an asset, server Apply Timed Change (Effect Id, Change, Tick Interval 1, Duration 5, Source) runs one change; applying the same id again refreshes it (an empty id gets a unique one).

6. Status effects

The same effect asset adds stacking and modifiers held while it is active.

Effective max is (Base Max + adds) × multipliers; the current value is clamped when the max drops. Nodes: server Apply Effect (Effect, Stacks 1, Source), Remove Effect (Effect Id, Stacks 0 = all), Remove All Effects; pure Has Effect, Get Effect Stacks, Get Effect Remaining Time (-1 = not active, 0 = no limit), Get Active Effects.

7. Downed, death & revive

States: EVitalCoreLifeState Alive, Downed, Dead. Nodes: server Revive (Health Fraction 0.5; minimum 0.01), Kill (Killer; ignores god mode and the downed state), Reset Vitals; pure Get Life State, Is Alive, Is Downed, Is Dead, Get Downed Time Remaining. Healing never raises the health of a downed or dead pawn: use Revive. On death, effects with Remove On Death are removed and sprinting stops.

8. Invulnerability

Blocked hits fire event On Damage Blocked on the server with Blocked set in the hit info.

9. Multiplayer

The component replicates by default. Every change is made on the server; nodes that change state are authority only and do nothing on clients. Replicated: stats, active effects, life state, last hit, kill info, bleed-out end, invulnerability end, god mode, exhaustion and sprint state. All timers use the server world time (Get Vital Time), so remaining times read correctly on clients.

RepNotifies turn changes into the same events on clients: On Stat Changed, On Damaged, On Shield Broken, On Downed, On Death, On Revived, On Effect Applied / Stacks Changed / Removed, On Exhausted, On Exhaustion Recovered, On Sprint Changed. On Damage Blocked and On Fall Damage are server only. Set Sprinting is the one call clients may make: it is forwarded to the server with a reliable RPC (the owning client only).

10. Engine damage

With Hook Engine Damage (default on) the component binds the owner's OnTakeAnyDamage, OnTakePointDamage and OnTakeRadialDamage. The engine's Apply Damage, Apply Point Damage, Apply Radial Damage (and AActor::TakeDamage in C++) are counted once, through resistances, armor, shield and kill credit. Point damage provides the shot direction, hit location and bone; radial damage provides the direction from the explosion origin. With Negative Damage Heals (default on), negative engine damage heals health.

11. Hit info & kill credit

struct FVitalCoreHitInfo: Damage (health lost), Shield Damage, Incoming Damage, Damage Type, Instigated By, Damage Causer, Source (credited actor: the instigating controller, else the causer's instigator controller, else the causer), Direction (travel direction), Location, Bone Name, Time, Periodic, Blocked. Get Last Hit returns it; Get Last Hit Angle returns where it came from relative to the owner's facing (0 front, 90 right, -90 left, 180 back) for hit indicators.

At death, FVitalCoreKillInfo is built: Killer is the source of the killing blow; when the killing blow had no source (fall, bleed-out, environment) the most recent damager inside the window gets it. Assists lists the other sources, most damage first, with their player states. Get Kill Info returns it and On Death passes it. Get Recent Damage Sources (server) lists the damage per source.

12. Fall damage

For Character owners the component binds LandedDelegate and tracks the downward speed while falling.

event On Fall Damage (Impact Speed, Damage) fires on the server; On Damaged fires everywhere as usual.

13. Save / restore

pure Save Vitals returns FVitalCoreSaveData: every stat (current, base max, min, base regen, delay), every effect (soft reference to its asset, stacks, remaining time, inline changes), life state, bleed-out time, god mode, exhaustion and a Valid flag. Store it in your SaveGame object; all fields are marked SaveGame.

server Load Vitals (Data, Restore Effects = on) restores it: effects are rebuilt from their assets, bases and modifiers are applied before current values, and events fire for what changed. Stats that are not in the data keep their state; saved stats the component does not define are added.

// Blueprint-equivalent C++
MySave->Vitals = Vitals->SaveVitals();
UGameplayStatics::SaveGameToSlot(MySave, TEXT("Slot0"), 0);
// ...later, on the server
Vitals->LoadVitals(LoadedSave->Vitals);

14. Stamina & sprint

Nodes: server Try Spend Stamina (Amount) and Try Spend Stat (Stat, Amount) spend only when the full amount is available and the pawn is alive and not exhausted; pure Can Spend Stamina, Is Exhausted, Is Sprinting; call Set Sprinting (from the server or the owning client). Exhaustion stops sprinting and fires On Exhausted; On Exhaustion Recovered fires when spending unlocks.

15. Debug & Blueprint library

Console variable VitalCore.Debug 1 draws every Vitals owner's name, life state, god mode / invulnerability / exhaustion / sprint flags, each stat with its regeneration and delay, and the active effects with stacks and time, above the actor. It needs a HUD (the default HUD class is fine) and does nothing in shipping builds. Get Debug Text returns the same text for your own UI.

Function Library UVitalCoreLibrary — category VitalCore. Every node accepts an actor or a controller (its pawn is used).

Events

C++

#include "VitalCoreComponent.h"
#include "VitalCoreLibrary.h"

// In your character's constructor
Vitals = CreateDefaultSubobject<UVitalCoreComponent>(TEXT("Vitals"));
Vitals->bCanBeDowned = true;
Vitals->InvulnerabilityAfterHit = 0.2f;

// Server: damage, effects and stamina
Vitals->ApplyVitalDamage(25.f, UDamageType::StaticClass(), ShooterController, Weapon, HitLocation, ShotDirection);
Vitals->ApplyEffect(PoisonEffect, 1, ShooterController);
if (Vitals->TrySpendStamina(20.f)) { Dodge(); }

// Anywhere: reads
const float Health = UVitalCoreLibrary::GetStatValue(TargetActor, TEXT("Health"));
Vitals->OnDeath.AddDynamic(this, &AMyCharacter::HandleDeath);

Public headers: VitalCoreComponent.h, VitalCoreEffect.h, VitalCoreProfile.h, VitalCoreLibrary.h, VitalCoreTypes.h (all structs and enums).

Troubleshooting

Credits

© 2026 Alpha XP — alphaxp.net · Support: support@alphaxp.net. Built for Unreal Engine 4.27 and 5.8.