RPGs Should be Unfair
A 'fair' RPG game immediately cuts the believability from a game. It slays engagement far more than a golden dragon, or a mushroom-man. A 'fair' game takes the fear out of the players, which robs RPGs of one of their unique abilities among games - death.
Let me tell you about the 'unfair' things my world did to my players. I say 'my world', because I don't consider myself responsible.
There once was a little necromancer, who became a demilich.
It's hardly my fault he stayed in the small temple he once lived in, even while it crumbled. And if he wandered the lands, killing people to grow his army of the dead, how am I responsible? That's just what necromancers do.
I can hardly step in, and rearrange the world, so that the players have a 'fair fight'. He slew multiple villages. He earned those hundred ghouls. Who am I to take them away?
Yes - one hundred.
AP: 2, Attack: 8, Damage: 1D6+2, HP: 8, DR: 2
Also the demilich, had killed an ogre, raised it as a ghoul, then used the armour from dead adventurers to cobble together a mixture of leather and chain armour for his new titan.
Four of the Night Guard (players) wandered through the snowy wastes, following a rumour, until they journeyed beyond the edge of the map. And there they saw the army of the dead, in front of a crumbling temple, with one tower remaining.
The dead cannot see with their eyes, but the nasty spirits which animate those bodies can see the souls of the living, like a fire in the darkness, so the dead turned to stare, then move, faster and faster, to drink the souls of the living.
The guards ran. And without any dice-rolls I said:
You run through the snowy wastes, pushing through the paths you made on your way here, and soon get away.
They made camp. They caught their breath. They started a fire, but as the Sun began to set, the dead came after them.
"We could just run again"
...or so they thought, but then they noticed the Fatigue Points on their character sheets, and knew they had to think of another plan.
The tower! We can circle back round, and get there before they do. We make our stand in the tower.
The demilich made sure his undead ogre remained to protect him. Once they arrived, in the darkness, they fought the creature for a moment, one almost died, and then cast a spell to control the dead.
By D&D logic, undead, massive ogres have 'lots of hit dice', and therefore can resist necromancy spells to control them. But I don't use gaming-logic. I use standard logic. Ogres are stupid, and so are the undead. So the ogre stopped, to listen.
The troupe heard the crackling of branches some miles in the distance, and knew the dead were returning for them. They wandered up the stairs of the last remaining tower in the ruined temple, and discussed building a basic barricade.
Of course they met the demilich at the top. And again, by D&D logic, he would have lots of hit dice, but in Fenestra, he only has lots of spell-power. One of the guards rushed him, and pushed him off the side.
You can faintly see him by your torchlight - a small, stunned, black patch on the snow below, slowly standing up.
So the elf - a useless character, with badly rolled stats, who had selected the wrong weapon for his size - asked the perfect question.
If the tower is crumbling, are the rocks up here loose?
Of course they were, so he pushed one off, right onto the demilich below. And without 'hit dice' or 'a high level' to save itself, the demilich received 2D6 Damage, and went 'crunch' instantly.
Then an 'unfair' number of ghouls returned, and the guards almost said their goodbyes to each other, before one remembered:
I still control that undead ogre. Can I make him hit the other ghouls?
A stiff little man-corpse can do very little when confronted with a giant, decked in armour, and wielding a tree-trunk like a hammer. So the other ghouls fell, one-by-one, as the guards sat on the wall, and had a little picnic with their remaining rations.
I had a lot of fun that day, finding out what the players would do. And if they all fell in battle, that would have been a shame, but still interesting. But I cannot imagine anything would feel interesting if I had reduced the ghouls to a mere twenty, for a 'fair fight', and made sure the undead ogre had a good 'saving throw vs spell', because of his 'hit dice', or allowed the demilich to survive a piece of tower falling on top of him, because of his 'level'.