Hey there fellow Diablo player! When it comes to defeating bosses in Diablo III, it’s crucial to understand their mechanics. Make sure to stock up on resistance gear specific to the boss’s elemental attacks. Use crowd control skills to immobilize them and deal damage safely. As for optimizing gear, focus on critical hit chance, critical hit damage, and cooldown reduction for most builds. Don’t forget to socket your gear with appropriate gems for added bonuses. When leveling, prioritize completing bounties and rifts for experience and loot. Experiment with different builds to find what works best for your playstyle. Happy hunting in Sanctuary!