I usually play 2 investigator games. I've noticed that the game is noticeably harder the fewer investigators you have, and that a lot of the difficulty scaling based on # of investigators doesn't do a great job compensating, something I thought Arkham Horror did a better job on.

For example, clue spawning and costs increase at the same rate the more investigators there are. No changed difficulty there. But then only twice the number of gates spawn in an 8 player game compared to a 2 player game, and it's always only one monster per new gate.

Then there's things that don't scale at all. Shub-Niggarath's monster spawning is deadly to a low player game, trivial to a high player count. The 2 clue cost of undoing Agreement conditions is unthinkable in a two player game, dirt cheap in an eight player game. Mysteries with a fixed cost like Crown of Serpents are ludicrously impossible for 2 players.

So we came up with a house rule to deal with this: treat the cost of all such instances as balanced for a 4 investigator game then scale off of that.

Examples;

Shub-Niggarath's "if there are 10 or more monsters during a reckoning, advance doom by 2" becomes "if there are (14 - (# of investigators)) or monsters during a reckoning, advance doom by 2"

Agreement condition's 2 clue cost becomes "half (# of investigators)"

Crown of Serpents....gets thrown into the garbage

We've found this to result in much fairer games for low investigator count teams, and more of a challenge for large teams.

This changes sound really good to me.