Healing potions become Healing Poisons

 I'm reading about how, if you eat too many vitamins, you can kill yourself. So in theory, overdosing on Healing potions should be a thing.

When Healing starts to Hurt

The Theory comes from this article on vitamins. If you eat too many, and its the wrong type, you'll do damage, and possibly die. 

Now, not to say that you should be rolling on the poison table every time players take a potion, but.. 

The Thought is this: Players who buy up lots of healing potions, and go into battles, sorta break the flow of the game, not the roleplay, that's another story, but the gaming part of the flow.

Standard games have a cost vs Benefit system, You pay a smaller cost, to gain a slightly better benefit, swapping where the benefit is, maybe you get an axe, its heavier, but it does more damage. then you go up level, it takes time, but you get a strength bonus. Over time, you 'pay' the costs to gain the benefits.

Ignoring 5e DnD long and short rests for the moment, more old school, the players would 'pay' for healing potions, which would allow them to return from a very dangerous situation, almost dying, to a point where they can live long enough to bandage up, return to town, mend their wounds, regroup, possibly researching the bad guy they're about to face, preparing for that battle, and then going out again.

The cost to buy them, would often be restrictive, at 2nd or 3rd level, you'd be lucky to have one in the group, by 5th-6th, everyone would have one, and in times when the game would usually end around 9th-12th, and players would go into negative HP, requiring a few potions to achieve the same effect, the balance was still there.

But then computer games.

You might remember Diablo, now, this huge HP buffer, stacked up with 10s of potions, small medium large, to allocate more and more HP per potion, completely broke this balance. and it bled into roleplay games. Players now expected to complete missions the FIRST time they entered a dungeon. Considering it a fail to need to retreat and regroup. 

I've seen groups, give up on a dungeon, because they got half way and had run out of abilities to continue. They went home, convinced the dungeon was too hard, even blaming me as GM, as if I was in charge of the Half Orcs that constructed this place, and filled it with strategically placed traps, guards and alarms.

no-wonder the youth of today can't follow through with a task. tsk tsk (take the bait, leave a comment)

So, games like DnD, instead of training their players as to the 'right; way of doing things, like good parents, gave into the childish cries of new players and added mechanics, such as partial and full rests, which pretty much take care of the healing potion carts that would accompany mid level players into dungeons.

So, I'm not going back that far, but the thought occurred, as I am mid rules on potions and poisons, that all potions should have decimal places of poison, and if you overdose, you'll trigger poison rolls.

This way, you can allow your players as many potions as they want, as long as they mitigate the numbers, chug down 5 lesser healing and a greater healing, and maybe your severed spinal column will heal too fast and you'll get a limp, or your muscles will cramp and heal too tight, causing pain when you flex.

Then, you've got a quest, for players to need to return to the town, and get proper healing, maybe from shannafria, players didn't leave because they failed. they needed to get rid of this 'curse' before they could defeat the Big Bad Guy.