You Do Need power plug adapter while traveling from Cambodia to Laos.

Here is Why You Need An Adapter

The outlet and plug type used in Laos are A, B, C, E and F and in Cambodia are A, C and G. This is how they look like.

Cambodia

In Cambodia, outlets of type A, C and G are in use.

Type A

Type C

Type G

Laos

In Laos, outlets of type A, B, C, E and F are in use.

Type A

Type B

Type C

Type E

Type F