History YMMV / HeroesOfMightAndMagic

** Ghosts in I and II. Every time a stack of ghosts kills a creature, it adds a ghost to the stack. These are especially difficult early in the game, as a half dozen ghosts can hit a bunch of peasants, kill 20, and suddenly you're up against triple the number of ghosts you started with. Because of II's "flying enemies have no movement restriction" mechanic, it was impossible to protect yourself from ghosts. You just had to wait until you had a high level army that could take the ghosts with no casualties.

** A series-wide example. If you are aiming to obtain or improve a hero skill upon levelling up, you have to pray to the RandomNumberGod that it will show up instead giving you skills that you don't want which will mess up your build. For example, ''III'' only offers two options, one of which is usually a pre-obtained skill. ''IV'' is like ''III'' but it has three options instead. ''V'' dials back to two options for main skills and abilities each, which is dangerous for those aiming for the Ultimate skills. Outside of SaveScumming (a luxury that cannot exist in multiplayer), you usually can't change the skills offered upon levelling up. There is a reason for the existence of Memory Mentors in ''V''.

** The Lord of Heresh mission in ''V'' can be pretty damn absurd in terms of difficulty. Sure, you get two cities and you only enemy has just one... but in order to even get to him you need do aquire a specific artifact, which requires winning two battles against a large number of high-tier units. Due to how the scenario is designed, you get at most two months to build up your forces, while Haven troops keep leaving you, your mines get randomly captured and two enemy armies invade your teritory. Before the time is up - and assuming neither of your heroes got killed yet, which is an automatic failure - you have to confront your opponent right in his city, where he has a huge army and maxed-out fortifications at his disposal. But there is one more thing which can make this scenario downright impossible - the hero defending the city is Godric, who was one of your main heroes in two earlier missions. If you developed him well, then you might suffer a case of HoistByHisOwnPetard, where you are defeated as a result of your own abilities.

** When it comes to ''III'', there was a ''three''-way split: playing it vanilla, playing ''[=WoG/ERA=]'' or playing ''[[VideoGame/HornOfTheAbyss HotA]]'' mods. Over time, a fourth group splintered off, using ''[=WoG=]'' solely for quality-of-life changes, but otherwise sticking to vanilla rules, units and their stats. Over two decades after its premiere, there is a rift in the size of Great Canyon when it comes to any discussion on how to "properly" play ''III''.

* ViewerGenderConfusion: The Rakshasa Ranis in ''V'' are muscular and have quite masculine faces. The only indication of their gender is the green sashes they wear over their pectorals.

* VindicatedByHistory: In light of the ''even more'' poorly received ''VI'' and ''VII'', ''IV'' and ''V'' were considered as such.

** In the first mission of the ''Dungeons and Devils'' campaign of ''III'', you're tasked with killing the Gold Dragon Queen. Does that sound difficult? Not when you consider that she's just a single Gold Dragon, who won't pose much of a threat to you if you've fought your way through the dozens of Green Dragons in her lair.

** You can do this to yourself - in fact, if you like winning the game it's recommended - in the second last scenario of The Pirate Queen in ''IV''. If you know [[spoiler:Pete Girly is going to betray you]], you can make sure to give him as many abilities that don't have anything to do with combat, like scouting and pathfinding so that he's a pushover during the final battle. That's him ''personally'', mind you - he'll still have a gigantic army with 100 Hydras in it, but those hydras are a lot easier if they're not backed by [[spoiler:Pete]] with Grandmaster Chaos Magic. His army is also not supported by any towns and just stays still in the middle of the sea throughout the scenario, meaning that you can just build up your forces at your own leisure before crushing him with overwhelming force.

** Colossal Caverns, from the second game. You have a year to get a million gold by exploring a large dungeon, capturing towns, claiming gold mines and acquiring resources and treasures to fund your way to the goal. It's a very long mission, but it's also quite well-designed.
** In addition to Colossal Caverns, the second game in general deserves credit for shipping with a lot of fantastically creative maps with tons of WorldBuilding and attention to detail - Ghost Planet, Plains of Aekon, Gates of Hell, Slayer Legacy, THUNK and more. The fact that Heroes 2's developers did this ''before'' the advent of [[GameMod Game Mods]] allowing scripted events really shows the extent of how well these scenarios were planned out.
** The Mandate of Heaven, in the third game, is a replica of the eponymous sixth ''VideoGame/MightAndMagic''. It features all sorts of references to the RPG, from towns and dungeons to the monsters you might find in the various region of the game and includes impressive attention to detail. This led to several other scenarios paying homage to the RPG series, such as the Xeen scenario in ''VI''.
** Myth and Legend from ''III'' pays homage to Greek Myth/ClassicalMythology, where the player controls Heracles, Perseus, and many other heroes in a large, detailed map of ancient Greece plus the underworld. It received a sequel in ''Armageddon's Blade'' called Pandora's Box.

** Castle Alamar in the first game, the penultimate mission for non-Warlock players. There's a giant maze in the middle of the map, and while the game hints that the Gargoyles will show you the way, you'll have to kill a lot of them in order to make your way to the enemy city. Castle Alamar is extremely well-defended, and is probably more of a challenge than the actual final mission.

** Steadwick's Fall in ''III'', which, as the last mission of the ''first'' Evil campaign, is a severe DifficultySpike. The goal is to conquer Erathia's capital of Steadwick within 3 months. The catch? It's guarded by General Kendal, a very powerful Campaign-exclusive hero[[note]]Thanks to two very powerful artifacts, his Attack and Defense is at a whooping ''19-20''. Even your most powerful hero with all the best artifacts you can get on the map can only have his best stat reach ''15'' or so.[[/note]], who also has an incredibly large army[[note]]Thankfully, he has no angels.[[/note]]. Not helped by the fact that the city's barricaded by heavy garrisons and extra cities surrounding the entire map. On your end, you can only carry over ''one'' set of heroes from the two previous scenarios while at the same time having no campaign bonuses. Not surprisingly, many players choose to beat this scenario by luring General Kendal with a decoy hero out of the city that is just far enough to prevent him from coming back in the same turn while a second hero takes the unguarded city.
** Tunnels and Troglodytes in ''III'', the last mission of the second Good campaign. It's a large map, making it difficult to control territory. You start with a Castle, a Rampart and a Tower, making it difficult to field a large army of a single type. The enemy, however, has five Dungeon towns, and there are creature dwellings all over the map, making it easy for them to outproduce you if you're not careful.
** The Pirate's Daughter in ''IV'' seems to have been designed to punish people who got complacent with the relatively low difficulty of the previous campaigns. This first scenario is EarlyGameHell defined, you start with a small army of weak units, far away from any town, while your two opponents start with two each, and will aggressively pump out units from day 1. It takes days of sailing to reach the nearest neutral town, and it begins poorly developed and is in area that lacks in resources. Just stopping to build it up is not an option, or else the Green player to your immediate east will bowl over you with their superior resources and numbers, but executing an attack is no picnic either, due to their decently levelled heroes and strong starting position. And before you think about just using your heroes to overpower it, they have an AbsurdlyLowLevelCap of just 12, and are both thieves, who take multiple levels to get direct combat skills and have them on lower priority compared to their scouting skills, which are useless in direct combat. If you can survive the early part of the game and knock out Green, things ease up a lot, but getting to that point requires precise execution.

** The Faerie Dragon scenario from the Campaign "Dragon Slayer" in Armageddon's Blade. While it is not hard, it is incredibly long as it requires your hero to trudge through multiple rough terrain (and often backtrack) completing random objectives to unlock the next area. Your hero will also hit the level cap in this scenario long before you get close to finishing, meaning that the latter battles are more or less just a waste of time as you gain nothing from them while potentially losing troops and have to backtrack, which is even worse if you chose this as the second mission, as the next one has the same level cap rendering all those battles a pointless slog as well. Finally, much of the enemies in this mission, due to the time limit, are trick bosses that require specific usage of spells or creature abilities to overcome, the most infamous of which is a stack of Nagas numbering ''3500'' (nagas seldom reach 100 in normal gameplay).

** Within the ''Heroes'' series itself, ''II'' and ''III'' definitely eclipsed the first game in popularity due to technical and aesthetic advancements, and are re-visited by players more often.