HoB finale encounter 1 - overlord cards

By Aaborre, in Descent: Journeys in the Dark

Hi

I have a question concerning the last part of the 1st encounter of the finale Blood and Betrayal in Heirs of Blood.

Text says this:

“There is a maximum number of Overlord cards the overlord can keep in his hand going into the next encounter. This number is equal to twice the number of heroes, and Overlord cards in the overlord's play area count against this maximum. If he has Overlord cards in excess of this number, he must discard cards from his
hand or his play area until the correct number is achieved. “

The text in bold is what confuses me. What does that mean ‘overlord cards in his play area’ Does that include discarded cards as well?

anyone who can explain to me the meaning of that phrase?

Some overlords cards from expansions may be in your play area.

In the base game there's none

I see. Thanks for fast response rugal.