In Episode 03 of my Universal Damage System series for Unreal Engine 5.4, I start actually coding the logic behind the damage calculation object classes—specifically the physical damage side (blunt, slash, pierce, etc.). The goal here is to take raw incoming damage and run it through resistances and critical hit logic, then return clean outputs that the rest of your game can react to. I’m keeping the system completely stand-alone, so you don’t need any prior series or course to plug this in and follow along. I walk through why I wrap damage calculation inside an object (data-driven flexibility as your game grows), then I build out helper functions like checking whether the target has a resistance to a given damage type and converting a resistance “level” into a multiplier via a data table. I also switch to easier debug numbers (like 100 damage) so you can instantly see whether math is behaving. After that, I implement a single critical roll per damage instance and apply a critical bonus correctly (example: 100 damage with a 0.5 bonus becomes 150 on crit). Finally, I show real debugging—what broke, how I isolated it, and the fix: making sure your data table row names match, and converting the enum to string before using it as a lookup key. Once that’s corrected, the resisted and critical totals print exactly as expected.