Hit points, Attack, and damage. The components of the padded sumo slap fight.

This comes up a lot more in Table top games than video games. A point where the fight is already decided or no one knows who is winning until 5 more attacks hit. For a while in 4th edition D&D the term Padded sumo fight came up when people realized that the monsters high hit points and other defenses while not being a high enough threat to the players perceptions. It's popped up in other systems; as stated 4th edition had a problem with the monsters just having too much HP to deal with in a 'fun' time frame, Dark Heresy for being a very lethal system has laughably easy ways to survive damage considering it's low to hit aspects, and Mutants and Masterminds has this effect alot where fights run a lot longer when it could be the players effectivly just finishing off the boss I set up while the only threat at this point comes from them rolling too low when taking damage. It's just not satisfying at those points and becomes a chore.

Pen and Paper combat takes a decently long time, online it takes a lot longer for magical reasons. When combat becomes a chore instead of an exciting situation people quit describing attacks and just rolling their most effective attacking against the most threatening target or weakest target, it honestly doesn't matter to the players at this point. They just want the fight over with and while the GM may have some surprises left they quit caring too and just want to get back to the "fun". Which is a big problem, as the entire gaming experience should be fun to some degree.

There a few factors in what causes a fight to be a boring grind, and like my title suggests  it's all about the abstracts used in games. The majority of games like the hit point concept, have 1 and your fine. They also like a simple way to reduce them, straight up damage rolls. Simple enough you can get how long you're expected, in a boring fashion, to take down a monster. Hitpoints/average_damage gives you how many turns it's likely to take down that monster in the bread and butter fashion. Though most games have an attack roll to hit the monster, making the formula a bit longer Hitpoints/(chance_to_hit*average_damage) making combat longer. In D&D and it's general rule of thumb 50% chance to hit a target of the same level you're effectively doubling the length of fights. Some system also let the defending player negate attacks leading to something akin to Hitpoints/((chance_to_hit*chance_to_negate*average_damage). Give a player a 50% chance to hit and the defender a 50% chance to ignore that hit and you've effectively quadrupled the length of the fight. At these stages you could reduce the hit points of the target to taste and arrive at something that would take an estimate few rounds. This presents a problem as the formula takes into account the player missing and the negation chance happening according to average static terms. Dice don't have memory and typically like to ignore averages in the short term scale, long term 10000+ rolls not so much. Generally called "swingyness" where a few rolls control the fate of a character you can end up with the monster in one hit your designed challenging monster can happen enough that you'll question dice randomness. On the other side the one hit mooks you send out could prove more effective than any boss encounter you carefully prepared.

How to solve this problem seem to be a dilemma in gaming at large and various solutions have come up for it. Action point systems let you reroll dice is a common one. Some others give you insurance that if you get taken out in one shot letting you ignore it that time. Either way a lot of systems require a lot of taste in how combat  works to enjoy it. I prefer mine a little more swingy. I'd rather have a battle short and over and deal with the consequences than to have the battle take too long.