Spanking
Spanking is striking the buttocks — most famously with an open hand, though paddles, hairbrushes, and other implements feature too — for erotic sensation. It's the most common and accessible form of impact play: the fleshy, resilient buttocks take it well, and a good spanking warms the skin to a glowing pink (heavier play can bruise). It spans a huge range, from a playful swat during sex to a serious, ritualized discipline scene. The mix of sting, warmth, and the power dynamic of being 'put over a knee' is the appeal. It's often a first step into BDSM.
The sting-turned-warmth releases endorphins and reddens the skin in a way both partners find hot, while the act itself — one person bent over, the other in control — is a clear, primal power exchange. For the receiver it's submission and sensation; for the giver, dominance and the satisfying sight and sound of it.
The receiver bends over a lap, bed, or furniture while the giver builds from light warm-up swats to firmer smacks on the fleshy part of the buttocks, varying rhythm and force and often mixing in caresses. It ranges from playful to a structured discipline scene with counting or scolding.
Strike only the fleshy buttocks (and upper thighs) — avoid the tailbone, spine, lower back over the kidneys, and hips. Warm up and build gradually, watch for deep bruising or broken skin, and keep a safeword. Aftercare — soothing the warmed skin and the receiver — rounds it off well.