You Do Need power plug adapter while traveling from Liechtenstein to Marshall Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Marshall Islands are A and B and in Liechtenstein are C and J. This is how they look like.

Liechtenstein

In Liechtenstein, outlets of type C and J are in use.

Type C

Type J

Marshall Islands

In Marshall Islands, outlets of type A and B are in use.

Type A

Type B