How Long Do You Wait Before You Houserule a New TTRPG?

[Theory of Games]

Reading this thread, I just realized the only system I've run where I never had to house-rule is GURPS. Such a great modular ttrpg

 

[aramis erak]

Fallout was session 3 of 3 for the group, but 6th session run, not counting session 0 sessions as sessions, and each group had 1 of those.
What was it? A separate Mr. Handy hit location table:

Roll	Location	(Considering changing to)
1	Left Eyestalk	1
2	Center Eyestalk	2
3	Right Eyestalk	3
4-8	Torso	4-8
9-10	Left Arm	9-11
11-12	Center Arm	12-14
13-14	Right Arm	15-17
15-20	Thruster	18-20

Why? Because the player and I both wanted to know which arm or eyestalk was hit!
So far, that's the only houserule.

 

[Autumnal]

I used to houserule…not heavily, but a steady-ish stream of small adjustments. The older I get, the less I do that. If a game seems to me to need significant houseruling, I’m likelier to just skip it. If done my share of rules design - some (I think) very good, some not so hot, but but with the mental west and tear of my own disabilities and caring for a mother with Alzheimer’s, it’s a big brain drain that isn’t very fun or rewarding anymore. So I look for games that work for me without any particular tweaking and have fun playing those.