I was reading through the Scout's Survivalist feature and noted that it is a manner by which a character can both gain skill proficiency plus Expertise in one shot. This got me wondering how many skills I could potentially get Expertise in for a single character. There have been several questions inquiring on maximizing a character's skill and tool proficiencies, but I haven't been able to identify any question discussing maximizing a character's Expertise.
For the purpose of this question, assume the following:
- Assume the character is allowed 20 levels.
- Only the character in question should be considered (i.e. no outside help).
- No epic boons.
- Any skill, feature, or item which allows the character to double their proficiency bonus for a skill is valid, it does not need to be called 'Expertise' to qualify.
- Use of any skill, feature, or item needs to have a tangible benefit. For example, if you need to be proficient in the skill in order to get the benefit of double the proficiency bonus, then that proficiency must be gained somehow to satisfy the pre-req. This avoids issues of having more Expertise than skill proficiencies raised by this question.
- Always-on is preferable to a short-term Expertise (such as what's granted by Skill Empowerment).
- Wish may be used solely within the confines of duplicating a spell.
- Multiclassing is permissible.
- Variant humans and feats are permissible.
- Any published background is permissible (i.e. no custom backgrounds).
- Magic items are permissible of any rarity except Artifact.
- No use of downtime to gain skill proficiencies.
I will consider the best to answer to be whichever one is able to come closest to gaining Expertise in the 18 skill proficiencies in the game. In the event that multiple answers can achieve this, then Tool proficiencies will be considered.