Spanking for the purposes of erotic role play sex can be quite common. If the submissive enjoys flogging or being whipped, they will enjoy being slapped with a hand.
It also enforces humiliaition, and the domination of the master / mistress, particularly if they are being held over their knee. It’s also easy to do, requires no equipment and can even be carried out with no fetish garments being needed either.
In most cases however this is just part of a larger roleplay exercise and even age-play might be included. This would be where the submissive would play someone much younger than their years for example a schoolboy being slapped by their headmistress etc etc.
This form of mild sexual torture is loved by both sexes, and enhances sex itself. The bottom area when being slapped will produce blood flow to the area affected and perhaps the genitals too.
Discipline you
It is basically a form of foreplay to the act of sex. The positions adopted can be many, over the knee is most common. But you could have your partner lay on a bed face down, or be on all fours and so on.
A session can be enjoyed by the dominant and the submissive. If it continues on too long of course its appeal will fade. This is only to be used as an interlude or returned to after a break. Roles can even be reversed and the tables turned on the dominant person, so they can receive getting a good discipline session too.
Although implements are not needed, you can still buy paddles and other flat devices of all sizes, to increase the area to be spanked - or if you get tired.
For further erotic reading seek out the poetry of Algernon Swinburne and Jean Jacques Rousseau, autobiography entitled - Confessions.