Compilation Error: Can’t Connect Pins Damage and Damage Instance

What It Means & How to Fix It in UE5

🧠 Why You’re Seeing This Error

This error means you’re trying to connect two pins that look similar but are not the same type — one might be a struct, and the other a float, class, or object.

In UE5 Blueprints, this usually happens when:

You’re using the Apply Damage or Any Damage event
You try to plug a float value into a pin expecting a Damage Event struct
You mix up the Damage Amount with the Damage Data object

💥 Example Error Message

Error: Cannot connect pins Damage and Damage Instance

🛠️ Common Blueprint Scenario

Apply Damage
    → Target: EnemyActor
    → Base Damage: [Connect Damage Instance object here ❌]

You’re accidentally connecting a Damage Instance (object or struct) into the Base Damage (which expects a float).

✅ How to Fix It in UE5 – Step-by-Step

✔️ 1. Understand What the Pins Expect

Apply Damage
    • Base Damage      → Float
    • Damage Event     → Damage Event struct (optional)
    • Event Instigator → Controller
    • Damage Causer    → Actor

If you’re just dealing damage, you usually only need:

Apply Damage
    → Target: EnemyActor
    → Base Damage: 25.0

✔️ 2. Do NOT Plug a Damage Event or Custom Object into Base Damage

Wrong:
    [Create Damage Instance] → Connect to Base Damage ❌

Right:
    [Float value] → Connect to Base Damage ✅

If you need to use custom damage types or data, use:

Apply Point Damage
Apply Radial Damage
Or custom events that accept your struct

✔️ 3. Use the Correct Damage Node for Custom Logic

Apply Point Damage
    → Base Damage: Float
    → Hit Result: Struct
    → Shot Direction: Vector
    → Damage Type: Class

If you’re passing complex info like hit locations, bullet direction, or custom types, don’t use Apply Damage — use the node that fits your data.

✅ Summary: How to Fix “Can’t Connect Pins Damage and Damage Instance” in UE5

Cause	Fix
Trying to plug a struct or object into a float pin	Use a float for Base Damage, not a struct
Misunderstanding node input types	Hover over pins to see what data types they expect
Wrong node for the kind of damage you’re applying	Use `Apply Point Damage` or custom nodes if needed

UE5 Blueprint Errors and Warnings