Myrhdraak
Explorer
Well, as we probably will not learn from this 38 years old campaign guy, I though I would try to share my rules journey for our campaign instead ;-)Yeah wonder if he's still using 1E as a baseline.
We started off with 1st Edition, but very soon I wanted something more "realistic" than D&D. I remember being influenced by Runequest at the time (this is back in the 80's), so I "converted" D&D into something similar to Runequest. We used d100 to hit, with critical calculated as 5% of the to-hit score, and serious hit as 20% of the To-hit score (with special effects for slashing, piercing and bludgeioning). A 5% fumble chance with extensive fumble tables. Starting to-hit chance at 1st level was 45% plus bonuses based on STR, DEX and INT. +5%/level for fighters, and +2.5% for magic-users. All AC was converted to "Absorbation", with platemail absorbing 6 hp. HP was distributed over the body so hitting certain bodyparts had a bigger impact. We also had an defense score that was around 10% at start but increasing with level (thieves had the highest increase per level). Size was its own ability and influenced some rolls and carrying capacity. This meant that I had to introduce abilities to all monsters I used, way before 3rd Edition came out. The system worked fine at low levels, but towards level 8-10 you almost never missed, and you had to roll serious or critical hit to damage high absorbing enemies. The whole system grinded to a halt ;-)
It also became increasingly complex so by year 1999 I converted all characters to Excel so all to hit numbers, etc. could be calculated on the fly. Still battle took long time. I remember also borrowing the skill system from the James Bond game, with different effects based on how successfully you rolled your skill check. It was really great and before its time. D&D had just started tampering with skills towards the end of 2nd Edition.
By 2008 when D&D 4th Edition came out, we were ready for change and embraced the new rules and started to convert it to 4th Edition. However, it proved to be hard, and it was not until 2010 there was enough stuff to be able to convert all characters fully based on the 4th Edition material. As D&D Next (or 5th Edition) already started in 2012 I started yet again homebrewing. I saw good things in 5th Edition that I liked (like bounded accuracy, backgrounds, inspiration, shorter fights), but at the same time we really liked the character complexity, power choice and team building that 4th Edition brought. However, 4th Edition was built around long complex battles and it was first after intesive simulations/calculationws I managed to change some of the core parameters of 4th Edition to allow it to be play both as 5th Edition (short 2 rounds combats with 9 encounters per day) AND 4th Edition (complex and strategic 6 round combats against complex foes and terrains). Now I am very happy and enjoy my 4.5 Edition.
I guess after 35 years, you like tinkering!
/Myrhdraak