Personally, the only rule I house rule to make the game a bit more fun in my opinion is that if I use 1 move action to get to an unexplored edge and still have another action left, I'll draw the new tile which will inflict the encounter/monster draw right away. That way, I can use my second action to either move away, or fight the monster that spawns. Fundamentally, I'm not really changing the game, which makes me feel a bit better about it.
Occasionally, if I'm playing with a group that isn't as tolerable about losing, I'll allow them to try and disable traps as they're sprung on us. This makes it a little more real for them, even though it's a bit easier overall.
Try the first option first, but if it doesn't work, using both options together should be enough to bring down the difficulty to a more enjoyable level for your son until he gets a better grasp of the game and wants to try it at a harder level.
Good luck!
Occasionally, if I'm playing with a group that isn't as tolerable about losing, I'll allow them to try and disable traps as they're sprung on us. This makes it a little more real for them, even though it's a bit easier overall.
Try the first option first, but if it doesn't work, using both options together should be enough to bring down the difficulty to a more enjoyable level for your son until he gets a better grasp of the game and wants to try it at a harder level.
Good luck!