u/RedYama98

Is it better to have physical and magical damage target the same defense value or separate? Currently my system issues a single defense value and damage is calculated as Attack Roll - Targets Defense = Damage. Magic resistance within the system already works in tiers such as Fire Resist 5, Cold Resist 2, etc. I want to keep combat simple and easy to understand. Is there benefit to having two separate defense values or should I use the single value?