Search Google images for a simple but not too simple maze with simple 90 degree angles. Right-click on the image and save to a folder in your documents.
Example
Find a simple maze image and save to a folder on your desktop called Game.
Change the Text to 'Your Name" + "Maze"
Delete all the objects except the floor and walls.. No Lighting, player start, or other non-3d objects.
Delete Ground
Drag Box out onto the workplace. Hit 'Accept'.
These are the settings I used to fit perfectly
In the Content Drawer Right-Click on the work area and create a new folder, called MyTextures.
Activate Modeling Mode {Shift} + {5}
Choose Create side menu and Click Box, a new menu will appear.
A new menu will appear . . . with Create Box details. Change Output Type to Dynamic Mesh
Drag the cube to one of your maze lines and hit "Accept".
It will turn yellow.
With the Cube selected change the Scale:
Scale X: 0.25
Scale Y: 1.0
Scale Z: 3.0
Switch to Model tools and choose PolyGroup
Select, Copy {ctrl} + {c}, and Paste {ctrl} + {v}. Then Move
Then Rotate . . .
Currently you are in Perspective view.
Switch to Top view if needed. Also change lighting to Unlit.
Finish creating an entire maze map.
Create a cube same way as last time.
Place it in a good location for a pit. Then select the ground and then hold {SHIFT} and select the cube that you want to make the hole with.
Boolean the two objects. This will subtract the cube from the ground. The order of the selection matters. Select the ground and then hold {SHIFT} and select the cube that you want to make the hole with.
Here is a short video.
You can still move the location of the hole once the Boolean in made, but it is permanent once you hit accept.
It is permanent once you hit accept.