Cracked paint can definitely be an eyesore in an otherwise well-decorated room. Cracked paint is a phenomenon also referred to as "alligatoring," and it happens when you apply a second or third coat of paint before the first coat has dried thoroughly. If your painted walls are in such a state, you don't have to live with them as-is. A few restorative strategies, along with a fresh coat of properly applied paint, can get rid of your cracked paint.
Put on your goggles and nose and mouth mask. Run the electric sander along the surface area of the cracked paint. You might need to use a step stool or ladder if you're dealing with higher sections of a wall.
Brush down the entire surface area of the space after you've sanded it. It's important that you thoroughly brush away all the dust. Apply a single coat of high-grade undercoat with a roller or paintbrush. Allow the undercoat to dry completely according to the manufacturer's instructions. If you're not sure of the timing, just give the undercoat 24 hours to dry.
Apply a single coat of the paint of your choice with a roller or paintbrush. Make clean, uniform strokes when applying the paint.