Portal Trap

You create a magical portal on a surface in an unoccupied space you can see within range. The portal occupies up to 5 square feet of the surface and is instantly covered with an illusion. The illusion looks like the surrounding terrain or surface features, such as mortared stone if the portal is placed on a stone wall, or a simple image of your choice like those created by the *minor illusion* spell. A creature that touches, steps on, or otherwise interacts with or enters the portal must succeed on a Wisdom saving throw or be teleported to an unoccupied space up to 30 feet away in a random direction. To determine the direction, roll a d8 and assign a direction to each die face. The creature can't be teleported into a solid object.
Physical interaction with the illusion reveals it to be an illusion, but such touching triggers the portal's effect. A creature that uses an action to examine the area where the portal is located can determine that it is an illusion with a successful Intelligence (Investigation) check against your spell save DC.