Question

do irregular surface also obeys the laws of reflection of light

Answer 1

Yes irregular surfaces also obeys the law of reflection at each point where the light is incident if we draw a line we can observe that all the laws of reflections will be obeyed I.e angle of incident=angle of reflection and all 3(reflected ray,normal,incident) lie on same plane

Answer 2

Irregular surfaces we see are  quite irregular at the size that our eye can detect.
But for the size of rays of light, their wavelength is very small..in terms of 100s of nano meters perhaps..

   So  the roughness does not matter.. light is incident at one precise point, and it gets reflected according to the laws of reflection..   However, different rays get incident on surfaces which are not parallel to each other... So the reflected rays are all in various directions.. So the scattering of light happens.  The surface does not appear so shiny.