You Do Need power plug adapter while traveling from Malaysia 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 Malaysia is G. This is how they look like.

Malaysia

In Malaysia, outlets of type G are in use.

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