Zhentarim Tactics

Source: FRHoF p. 41

Prerequisite: 4th

You gain the following benefits.

Ability Score Increase. Increase your Dexterity or Charisma by 1, to a maximum of 20.

Retaliate. Immediately after a creature within 5 feet of you hits you with a melee attack, you can make an Opportunity Attack against that creature.

Versatile Merc. When you finish a Long Rest, choose a skill in which you have proficiency. You have Expertise in that skill until you finish your next Long Rest.