I don't think you have to accept the premise that rules can be perfect to see value in trying to improve them.  A ruleset has a lot of rules (or at least, most do) and very few of them do everything you want right out of the box.  Sometimes a player wants a character that seems like an interesting concept and there are no concerns about power-level, but it just doesn't exist yet.  Building a new class before the publisher gets around to releasing it adds options and is one of the best reasons to tinker with the rules.

A second reason to tinker with the rules involves improving game play.  If the average damage of a single attack is 30 and characters are 'perfectly healthy' at 1 hit point, but dead at -10, it might not fit with the types of games you want to run.  Adjustments to when death occurs or how damage can be soaked fit into this category.  Rules can go in the opposite direction, too.  A triple-confirmed critical resulting in instant death adds lethality and based on what genre of game you're emulating might seem worthwhile.  A few relatively minor changes can have profound impacts on how the game plays, and if everyone understands what they are and there's group consensus, there's nothing wrong with that.

The third major category of rule changes involve actual fixes to the rules - sometimes if you follow the rules exactly you run into a place where the rules are silent or contradictory.  Publishers issue errata, so once again, makes sense to address it as a table rather than waiting for the publisher to issue a ruling.

A collection of tweaks might collectively be very minor.  A binder with 300 rules might only come up once per year if the base rules are pretty clear and work well, but if the game doesn't really do what you want they might be pretty major.  Taken far enough, you have a new game. 

My friends and I ended up in that place.  We don't pretend to be playing D&D, but someone familiar with D&D or other RPGs would certainly recognize it.  We continually update, modify and clarify our rules based on playtesting.  For example, we had a special ability (like a feat) that let you take a penalty on attack rolls and get a bonus on defense.  Turns out, it was a pretty good ability for people that never make attack rolls (like Wizards casting spells).  We thought about requiring an attack roll, but we didn't like the visual of warriors swinging their swords while they walked through the forest or that a group of warriors approaching a castle wall while the defenders peppered them with arrows couldn't get a benefit.  We ended up settling on allowing the benefit unless you do something that requires a standard/full action that doesn't involve an attack roll.  That prevents most spells (but not spells like burning hands) but it also doesn't allow for a dragon to defensively stomp an area (ie, an area attack that doesn't require an attack roll).  As a result of the tweaks we've made, we think we've got an ability that does what we want when and where we want it - but as we continue to playtest we might adjust it in other ways.  We might decide the benefit is too much or too little, or we might decide DR works better than a bonus to Defense - but the only way to know is to keep an open mind about how the game is working.

Ultimately, we want a game that's mechanically robust (the rules are clear on how to resolve most situations), the rules are easy and quick to apply (ie, we don't want to calculate the acceleration due to gravity with consideration for terminal velocity of humans and dragons) and we want gameplay that is consistent with the type of heroic fantasy we're playing. 

Making your own rules is a lot more work and can be a little humbling - it turns out that not every idea is good - but tweaking rules can make the game better based on objective criteria (ie, resolution is faster if we remove these 4 steps) and subjective criteria (and I like the Debilitating conditions we have more than tracking damage on a particular body part).

Of course, there's also nothing wrong with letting people decide what's fun for them.  Not everyone wants to play in a game with house rules, but if they are okay with it, there's nothing wrong with trying new things. 

Is there a strong urge to make changes to RPG rulesets?

Not necessarily. If you'd asked me this 20-25 years ago, I would have told you that my observations at that time had been that people love to dick around with various versions of D&D. They don't do a whole lot of tweaking of other RPGs. The same DMs I gamed with who had the most houserules for the D&D game played so strictly by the book when running Cyberpunk or Rifts.

My observations have mostly held over the years, though tweaking of other-than-D&D games does seem to be a little more common than it used to be. On the other hand, WotC versions of D&D seem to me to be tweaked less than TSR versions of D&D. This would tend to actually uphold my original idea that there is something especially tweakable by pre-millennial D&D.

But that's not what I think is going on. Because I myself am the greatest exception to my old thesis. I do a very BtB 1E game. Am I really just rising above the almost brain-washing effect TSR D&D has on gamers to force them to tweak the game?

I don't think so. When I look at what I get out of running such a BtB game, it's because when I read the odd rules in the DMG, it inspires me. It triggers my imagination. I have a real love for the ideas in there, and I want to share those ideas so other gamers can experience them, too.

And when I think back to those old DMs who houseruled the hell out of their D&D games, I see the same thing in them. Here's something I created that I love. I want to share this thing I love with all of you. He would always get excited when we'd play one of his homebrew races. When it came to running Cyberpunk, he didn't need to tweak the rules, because the game itself was something he loved that he wanted to share with us, since we didn't play Cyberpunk other than when he ran it.

So I think the real underlying motivation is to share something that we see from a unique point of view that we love. This better explains why so many people tweak while others are steadfast BtB, and why some games seemed to get tweaked more than others.

I'm less convinced about notions of adjusting the rules to fit the campaign. I put my campaign before the rules, and yet I still run BtB. Because writing house rules is still putting rules first. It's just a different set of rules. Putting the campaign first means viewing the rules as a set of tools. A hammer drives a nail. It doesn't tell you what size boards to nail together or in what configuration. It doesn't tell you what to build. I could still construct the same frame with a power drill and screws or joints and wood glue. The hammer is not the house, and the rules are not my campaign.

Quote from: Lunamancer on May 20, 2021, 08:13:48 PM
On the other hand, WotC versions of D&D seem to me to be tweaked less than TSR versions of D&D. This would tend to actually uphold my original idea that there is something especially tweakable by pre-millennial D&D.

I don't know about this.

I can't play WotC D&D without tweaking it. Especially not 5E. I don't look at it and see a fantasy role playing game, I see a superhero game if left untweaked and played as written. But I can play BECMI, or AD&D (both editions) without tweaking them if I want to, and they seem like fantasy role playing games. And I didn't run or play 4E for any appreciable amount of time until I returned to older editions or Pathfinder for fantasy role playing games.

Quote from: Dropbear on May 20, 2021, 10:27:58 PM

Quote from: Lunamancer on May 20, 2021, 08:13:48 PM
On the other hand, WotC versions of D&D seem to me to be tweaked less than TSR versions of D&D. This would tend to actually uphold my original idea that there is something especially tweakable by pre-millennial D&D.

I don't know about this.

I can't play WotC D&D without tweaking it. Especially not 5E. I don't look at it and see a fantasy role playing game, I see a superhero game if left untweaked and played as written. But I can play BECMI, or AD&D (both editions) without tweaking them if I want to, and they seem like fantasy role playing games. And I didn't run or play 4E for any appreciable amount of time until I returned to older editions or Pathfinder for fantasy role playing games.

My old school 8th level fighter feels like a superhero.

Quote from: Sable Wyvern on May 20, 2021, 10:22:49 AM

Quote from: Trond on May 20, 2021, 09:12:32 AM
Some rules books actually encourage house rules, saying things like "it's important to note that these are only guidelines, and the GM should discard the parts that don't fit".
I usually simplify a bit.

The big one is Rolemaster though; it definitely has some elements that add to the fun, but I don't think I'd ever want to run it as written.

I literally rewrote RMSS (other than Spell Law and Arms Law, pretty much in it's entirety). It was a project I had long planned, and finally got around to a few years ago. Then ran a fun 18 - 24 month campaign. There are a few further tweaks I'd make if I went back to it again, but I was mostly happy. Of course, I had 10 solid years of playing basically nothing but RM2 and RMSS to draw on.

I'm currently running Traveller, using the MongTrav 1e playtest document as the foundation, with bits of CT, T:NE and T5 bolted on.

My next game is planned to be ACKS, with a mere half-dozen pages of fairly straightforward house rules (many of which are actually just clarifying which optional rules are in use). Oh, plus hexcrawling rules adapted from the Alexandrian.

I also used it for a number of years, and then brutally simplified it, and used the online RM1 character generator. I posted a number of points in these forums years ago. The players said they really enjoyed RM, and didn't get why it sometimes gets a bad rap, so I had to point out how much I had tweaked and streamlined it. But the resulting system is a lot of fun, and definitely still a variant of RM, so I'll give ICE that.

Quote from: Pat on May 20, 2021, 11:29:39 PM
My old school 8th level fighter feels like a superhero.

Only after 120,000 XP though, lol.

The rules are my lego set, shall I not step on them barefoot? If you prick weapon speed factors shall that guy not bleed? Once more into nerfing magic dear friends, cry "gestalt!" and unleash the dogs of esoteric meta calculus!

I don't think that it is so much changing the rules, but customizing them to our satisfaction for play.

Quote from: Omega on May 19, 2021, 10:27:50 PMNot as many people change the rules as it os oft believed. Most are perfectly fine playing a game as is. Pretty much most games I've played as a GM were that way unless changing the game was actually required.

Your experience is different than mine as I've never played an RPG campaign with a GM that didn't change the rules. However, oftentimes they don't realize they've changed the rules and are just playing it wrong. But they like it the wrong way so that's effectively a change.

Changing rules isn't unique to RPGs. Boardgamers have their variants, video gamers have their mods, cooks tweak their recipes, and even movie buffs make fan edits. It seems like a universal desire.

I'm probably at the extreme end, having gone past modding to bespoke systems.

I ultimately just write my own systems for each game I run. I've got two alternate systems I built for World of Darkness derived campaigns, my own fantasy system, my own D6-based Star Trek system and am currently banging out my own Robotech/mecha system for a campaign.

I am normally trying to customize things to fit a homebrew setting.

Some rules require tinkering because they suck, such as Mongoose Traveller 2nd edition.

Because rules where meant to be broken. 
Im a dork

Quote from: horsesoldier on May 25, 2021, 09:27:57 AM
Some rules require tinkering because they suck, such as Mongoose Traveller 2nd edition.

i have the 2nd edition but haven't dug into it, what would you suggest changing other than "buy different edition"

Quote from: horsesoldier on May 25, 2021, 09:27:57 AM
Some rules require tinkering because they suck, such as Mongoose Traveller 2nd edition.

Believe you me, the playtesters tried their damnedest to make it an uprated version of Mongoose Traveller 1st edition but we were ignored.