How severe does a punishment spanking need to be?

I have been wondering about the same thing. To me, the spankings depicted in most of the stories found here seems highly exaggerated and unnecessary brutal - especially when given to minors.
My experiences with _punishment_ spankings are limited to those I occasionally received from my mother. They consisted of 10 - 15 brisk smacks on my uncovered bottom delivered in about just as many seconds.

I have considerably more experience with _play_ spankings, which are of a different kind entirely. Certainly there has always been a punishment aspect to these spankings as well, but only as a mental backdrop. Causing any real pain or distress has never been the point.

Regarding emilka's comments. I did receive spankings from both parents, all with the hand, I believe, and not on the bare. A few at school with a yardstick while holding on to my knees, and they were applied to my jeans.
Several minor things apparently added to my interest later on.
Many of the spankings in fiction go way beyond what occurs and should occur in real life. That said, a former acquaintance said her mother applied the hairbrush to her bare bottom.
Additionally, 95-99% of the mostly role-play spankings I got from Mrs. Often were on the bare. Somewhat painful, not excruciatingly so. Had we begun earlier, who knows? Severe or damaging results were not the aim, nor need it be.

One man's experience and opinion - mine.

In fiction and fantasy, a punishment spanking should be several minutes long, intense, showing shock, embarrassment and serious pain. (no blood/raw flesh or torture) Tears, crying, sobs, kicking, pleading, hot/very red bottoms, red lines, and all forms of histrionics all work for me.

In real life, I practice HOH/DD. The women I have had relationships with were all informed early on if they violated the rules they would be subject to my discipline to include a spanking. After discussion, some hit the road but most accepted the ground rules. I am easygoing and not the controlling type but I made it clear I would impose serious consequences for breaking our rules.

A punishment spanking I administer is relatively short and not that severe. The butt smacking is important but only part of the punishment. The confrontation, discussion, pronouncing sentence (spanking), the wait, the prep - placing the chair, lowering her pants all elicit more sniffles and tears than the actual spanking. Twenty to sixty seconds of brisk, crisp slaps produce a pink and very uncomfortable bottom and it is over. No agony or screaming or "thought it would never end" kind of pain.

A play spanking can last thirty minutes or more and is often harder than a punishment spanking. A grown woman with the right mind-set can take and enjoy a lot of hard butt smacking. This same woman can be close to tears before a punishment spanking begins.

Is the question about stories on here, or real life?
Surely in real life, to quote the Mikado, "The punishment fits the crime"?
The punishment for perhaps forgetting to take the trash out would not be the same as the punishment for deliberately overspending on the credit card or driving the car when not insured or even under the influence of alcohol?
Also dependent on the person about to be punished. The sinner needs to be brought to the same state, no matter if they are a quarter-back or a cheerleader, but how you get them there is likely to differ greatly.
So, what I am trying to get across is that the punishment spanking needs to be appropriate to the crime and sinner both.
On occasion a quick otk hand-spanking is quite sufficient and can be elevated by doing it in company or even public, where the embarrassment is far more painful than the spanking.
Other times it may consist of a damn good thrashing with a belt or paddle or even a caning designed to leave marks as a reminder.

An interesting debate but one where the evidence is unreliable because, apart from recollections of real punishment spankings experienced or observed when we were younger, few of us are likely to have any experience of the real thing, delivered to an unwilling spankee.
The evidence that we can rely upon comes only from spankings delivered to willing spankees, or at least spankees who can enjoy being spanked, even if not on this occasion.
I have experienced being spanked for real, when much younger, but have no experience of delivering a real spanking to an unwilling recipient. I have however, twice been lucky enough to be invited to deliver a real punishment spanking to women who normally enjoyed being spanked but who felt they deserved a proper punishment and who did not want to enjoy the experience. I pondered how to do that and concluded that all I could do was to up the severity until "the pain overcame the pleasure".
One of those occasions is detailed in our story "A Proper Punishment", co-written with the spankee, Margaret Jane. I have to say that it was a remarkable and memorable experience for both of us.

Geoffrey Stirling.

Whilst on my latter years, my spankings have virtually all be recreational (role play etc), I was a bit of a swine growing up and so my mum, aunty Sheila and my gran all had me over their knee of a fairly regular basis. Mum used to smack hard with her hand - occasionally a hair brush if I was very bad but this was quite bearable almost pleasant as I got older.

Aunty Sheila likewise was quite a slow even paced spanker but boy did she make them count when she wanted to.

Gran was a retires teacher, she knew exactly what she was doing. If I hadn't been too naughty I would get a few slow and regular smacks, but when very naughty, a cascade of slaps would set my bottom alight and were by far the most effective at correcting my behaviour. This were the only spankings that did not arouse me after puberty.

Interesting debate. My 2c in a story:
Anything too brutal leaves me cold.
Half a dozen slaps with someone's hand is just silly.

Play is another matter. Anything from a firm swat to a real hiding works depending on the mood I'm in.

As someone who has received plenty, I can state that the answer to this is very simple: severe enough to distinguish it from any other sorts of spankings that couple may engage in. And by "severe" I don't mean just amplifying the force involved. That may be a factor, but the practical execution may be a matter of upping the force just a bit, but doing so in conjunction with perhaps increased pacing to make it harder to process, or with an implement the sub does not like. The other factor that someone else mentioned is treating the incident as a punishment: making the sub understand why this is going to happen, the Top's feelings of hurt, anger, or disappointment, the elimination of any sexplay before or after, and genuine scolding. (I also agree that length is better shorter, BUT -----and this is a but for those with experience-----depending on HOW length is used, marathon durations can be very effective, but they have to add to the unpleasantness not turn unpleasantness into blissful subspace. I have found that VERY long durations will turn a pleasant burn into a mounting one that results in a 'when is this going to end?' regret.

But to the initial point, severity alone is just brutlality. The point of punishment is to change behavior, eliminate guilt, remove resentment from the party offended by the miscreant's actions, and essentially to demonstrate that inappropriate conduct has unpleasant consequences within that couple's dynamic. This can be done very effectively without doing something that leaves any undesired damage. but the specific conditions will change from person to person and not be something anyone can advise as a one-approach-fits-all recommendation.

(Edited afterwards to add: All this is presuming consensual adult spanking in a disciplinary context. Child spankings are another matter and belong in the realm of fiction where what happens is just a matter of the reader's taste. )

The entire paragraph pretty well summarizes my idea of a good spanking. Most stories I encounter on the internet are overly severe, while what you have described sounds right.
(Refer also to my earlier comments in this thread.)
Much of spanking involves the act in itself more than the pain involved. I'm thinking of the embarrassment, the accompanying scolding and how this reaches within the spankee. This may well result in a little mental age regression, especially in adults, as the spanker, (possibly the spankee), would desire.
Again, good hand spankings, particularly F/m and F/f, are more difficult than implement ones to find.

Thank you for that comment. What you describe so perfectly are the sadistic thrashings often shown as 'common place' on some video platforms which are essentially abuse.

That is not what punishment is about. It may rock some boats but my hubby would never contemplate such an act.