The Complete Enchanter

You work enchantments nto your natural persuasion, deception, intimidate and perform skills, and greatly reinforce your innate presence.

While this spell is in effect, for up to 1 hour while you concentrate:

• You have advantage on charisma ability checks and gain double proficiency as though expert in the skill.
• When you speak, anyone who can hear you within 300’ hears you perfectly, even over other noises and even if you whisper.
• When you speak, anyone who can hear and understand you is inclined to stop and listen. Your presence is such that those who can see and hear you must make a charisma save to avoid ceasing all actions in order to listen, similar to the effect of calm emotions. Those engaged in combat have advantage on this saving throw. This affect lasts for 1 round per caster level. It is broken by any combat actions the affected become aware of. Once a subject has saved vs. this effect, they are immune to it for 24 hours.
• The attitude of anyone affected is improved by 1 level, toward yourself and anyone obviously associated with you.
• You have disadvantage on hide and disguise checks.

The effect on others is not a magical or spell effect. It is instead a reinforcement of the caster’s inherent social skills. Since there is an enchantment component laced through the speakers voice, resistance and immunity to charm applies.