A whip in the hands of a Whip Expert turns a whip into a weapon with the properties of finesse, light and reach of 15’.

A hit with a whip from a whip expert may disarm, trip, or restrain a large or smaller creature if the creature fails a Strength  or Dexterity save (creatures choice). Attacking with a whip this way deals no base whip damage.

While restrained the WE must leave whip entangled in the creature.  The creature may spend its action to free itself. The whip master may release the creature as a free action. 

A disarmed creature drops one item it was holding (WE choice) at its feet.

A tripped creature becomes prone. 

The DC of a whip expert is equal to 8+proficiency bonus + ability score modifier for attack ( strength or dexterity). 

As a bonus action the WE may use his whip to do a variety of tricks like:  pull a lever, snuff out a candle or torch, knock a small, light item off a table or shelf, attach the whip to a sconce to swing over a fissure or pit, deposit a disarmed item into an empty space or free hand. Easy checks should be considered automatic. The dm will set the dc of the ability check (acrobatics) as normal, but the WE has advantage on the roll.

If circumstances permit while using a whip, Charisma (Intimidation) and Animal Handling checks are made with advantage.

Restrained condition-

• A restrained creature's speed becomes 0, and it can't benefit from any bonus to its speed.
• Attack rolls against the creature have advantage, and the creature's attack rolls have disadvantage.
• The creature has disadvantage on Dexterity saving throws.