3.5E Style Attacks of Opportunity for 5E

From the introduction: 5E is designed primarily for Theatre of the Mind style gameplay. Players who prefer mini-based tactical combat may take issue with a system like 5E that allows for easy disengagement. The system presented in this document basically marries a simplified 3.5E Style AoO system to 5E’s existing mechanics. An alternative for those that prefer Minis and Mats.