Master of Magic/YMMV


 * Complete Monster: Rjak. There's no use in diplomacy. He's Death Magic incarnate (what do you expect from someone who looks like a ringwraith?) and is always aggressive and hostile.
 * Which is why some players play as him just to be sure he won't be against them.
 * Tauron probably counts as well. He's supposedly not even human; he's an otherworldly demon, according to his lore, and as the game's resident master of Chaos magic, an endgame scenario featuring Tauron is pretty much guaranteed to end in Armageddon.
 * Fight Scene Failure: The combat animations frequently involve no contact between opposing forces at all. War Bears, for example, damage their foes by nodding at them.
 * Game Breaker: The infamous Wraith: or Shadow Demon rush, as well as some of the high end spells, especially Armageddon, that provides a nigh-infinite supply of mana. Or paladin rush. Or a fleet of catapult-armed ships under Flight, Eldritch Weapon (optionally) and Spell Lock (dispel is hindered even more with Archmage, Runemaster and/or Sorcery Mastery). Or the self-maintaining time stop. That is, once you get resources to pull such tricks...
 * In the original version, a stack of two or three paladins could easily defeat pretty much anything the enemy would throw at you. They were later nerfed.
 * A certain combination of traits allows a person to craft items at quarter price and then sell them for half price. That is, you spend 50 mana making a weak sword with listed price of 200, then break it for 100 mana. While it takes time to create a weapon like this and picking those traits cripples your spellcasting ability, it becomes very, very easy to very quickly start making items that cost thousands of mana (which you can do much faster than actually making thousands of mana), which means what little magic you can cast you can cast lots of -- and any heroes you get are going to be wearing some very, very nice equipment.
 * Best way to run this is to have five blue picks, which lets all your heroes have no-maintenance un-dispellable Flight, as well as "bastard invisibility" (the AI can still see you, but can't target you with ranged attacks although spells and spell-like powers still work) and Magic Immunity. If you manage to get another couple of blue books during play then things get even sillier. Also, once you have a mana reserve you can put all your mana production into casting skill and research, especially the former.
 * Black Channels. Elite War Trolls. Your trolls are stronger, cost basically no upkeep, and unlike most Black Channeled units, still heal because trolls regenerate. You don't get any XP with them, but that's why you do this on those you've already gotten up to Elite or Ultra-Elite...
 * Life magic has a spell that doubles the income of a city and another spell that makes citizens euphoric, thereby canceling all rebellion within a city. Combining these two spells on all your cities and jacking up taxes to three gold per turn will essentially give you an unlimited amount of gold, to the point where you can build a city or massive army from the ground up in just a few turns. Then again, gold is rarely in short supply late game, and food is more of a limiting factor on armies than money, which is where Nature magic comes in ...
 * Many Game Breaker strategies are based on investing all starting picks in one spell school, which allows picking some high-level spells from the start. While it takes a lot of time to actually cast this high level spell, once it's done you get unstoppable warrior (or some other overpowered thing).
 * Hilarious in Hindsight: Tlaloc is an anagram of Lolcat.
 * I can haz Spell of Masturi?