Help!

Is it possible to make a wall that npcs can pass through but not players? i have run into this problem a lot and always thought the solution would be NPC Clip, but im not completely sure! HELP!

player clip texture I think, or just clip.
I think any of those will do. But not NPC clip.

A brush textured with the playerclip texture.

Late.

I think the Clip texture blocks both players AND NPCs.

Player Clip does not block NPC’s only players.

I said the Clip texture, Not the PlayerClip texture.

EDIT: I was wrong: