Well it’s written up now, so I guess you can decide what depth of magic I’ve had to do vs how much it is just explained by sitting down and testing how things work 😛

https://mhloppy.com/2026/05/mechcommander-weapons-left-arm-bug-fix/

Weapon placement thought was before I took a closer look ingame and noticed how wacky the effects are.

Loadouts, true. Battletech as a system always has been kind of prone to convergence when over-optimised though, usually on energy weapons and specifically the Clan ERPPC, ERLLaser and LPulse. Environment effects and the newer damage-type-resistant armour can affect that, as with combined arms; a Hellstar will eat mechs and tanks for breakfast, but can’t do anything to infantry. They have been tweaking the rules lately to even things a little but the need to keep statlines the same to avoid invalidating decades of unit designs means there’s only so much that can be done on tabletop rules.

Imo making small changes to the exe (when it has debugging symbols available like both MC1 and RoN do) is pretty low-hanging fruit in the grand scheme of modding, and the tools and some beginner-friendly tutorials for getting started have been around since at least 2020 or so. Since working on RoN patching I’ve been perpetually surprised by people’s generally near-complete unwillingness to engage in learning how to do it given how fantastic some of the learning materials that have come out are and how much power it gives you to change things.

Trying to replicate the position of stuff in the loadout feels a bit strange when the mech editor for the game doesn’t even support choosing component locations and the printouts for the mechs won’t tell you where things are, but god speed in your pursuit of flavor 😛

Thinking about it now, I kind of wish there was a (..well done) modern remake (or like.. SEQUEL!?) that allowed for a bit more depth in mech customization. Customizing and iterating on loadouts is one of the big appeals of the MW/MC (and HBS Battletech) games for me, but it’s so simplistic in MC1. I guess in a way it matches the relative simplicity of the combat though; there’s not much reason to try most of the loadouts because slapping XYZ weapons on a mech if you have them is just stronger lol. I think the only time I changed loadout strategies much is when I was defending a base with a known repair bay (switch to using more ammo-based weapons), but I otherwise just kept a mental list of like 10 weapons to choose between and barely touched the rest of them. The curse of player optimization I guess 😔 Edit: stuff like being pushed to switch loadouts based on mission environment would’ve been great too, like (if heat were modeled in game mechanics) hot/cold biomes, fighting enemies that use a lot of AMS, fighting areas with lots of terrain (bad LoS) etc so that there’s an actual reason to tweak the loadouts.

MW5:Mercs had a short-lived “MechCommander” mod that I would’ve definitely tried out if it was still being updated. Something like an official / more polished version of that I’d be pretty happy with.

The modder’s curse, seeing something not-quite-right and being compelled, like a vampire seeing a pile of loose change, to sort it out.

Before the update I was going to say that you may have been underestimating yourself given that what you had earlier was more progress than had been made on this in 30ish years. Shoulders of giants and modern tools etc but still.

Had been noodling a little but I suspect I’m generally a much slower operator; was thinking about something that would try to get as close as possible to the mech’s usual loadout distribution for consistency/flavour, but I’m not sure weapon location has anything to do with where the visual effects (muzzle flash, projectile etc) fire from. Probably in one of the unknown filetypes in Shapes, .hsp probably. But that’s just cosmetic.

Ah for fuck’s sake, I got a brain worm thinking about why the code I was looking at didn’t work, and every time I stopped working on it I just ended up coming back. Luckily for both of us, for the two weeks right before you left your comments I’d actually been doing some hardcore work on Rise of Nations and the time estimate I gave for how long it would take to fix assumed my level of skill from before my patching spree. Because I did that intensive patching work, I’ve actually gotten meaningfully better at a few things. Still not “fix it in a few hours” better, but 1 day instead of 1 week.

I’ve managed to undercover the cause and implement a patch (albeit a bit of a janky one) which correctly distributes “large” weapons across both arms and side torsos instead of just piling it all into the left arm. I’ll do a writeup about it later and leave RiZZen a note, but I was right in my initial assessment that it wasn’t that hard to fix. https://imgur.com/a/vlFGILI

Something interesting about this is that both of my pilots punched out / died after I blew off their left (?) arm. Based on that, this proof-of-concept change might have actually placed the engine or cockpit in their arm LOL.

Well, on a whim I took a stab at finding the game (exe) code that handles placing weapons, and I’m pretty sure I found it. After making a very blunt change, I seem to have placed all weapons in not-arms and sensors in whichever arm is the left arm on the paperdoll (I don’t remember if the paperdoll is mirrored): https://imgur.com/a/oopSVvA (the weapons lists are image edits so that the full lists can be seen)

I expect somebody with my level of competence could probably have a reasonable solution in a week or two of work, or someone more competent than me could do it in a couple of hours (my thing here isn’t a solution, just a test that I correctly identified the code).

On a stray thought I did take a quick poke at the arm thing; as far as I can tell it’s sorting weapons when you begin a mission. I’d edited a mech in a pre-mission save to have an autocannon in each arm, but after beginning the mission the mech and its entry in the temp folder was back to one-arming it. Presumably the temp files do something but again this looks to be on the exe end of things.

The ModDB articles do touch on it in “loadouts” but it sounds like mostly speculation likewise.

Heat I don’t blame them for cutting. I could see some decisions like being fully sinked for max rate of fire vs a “bracket” build that can use all its short-range guns, or all its long-range guns, but not both, vs an “alpha” setup that does disgusting damage then jumps away to take a nap, but I suspect it’d be far too much micro in a game that already has a fair bit.

I’m pretty sure it does have ammo explosions, or at the least losing ammo to location destruction, which I suspect had a few players scratching their heads when a mech died or ran out of ammo too fast.

Man, the guns-in-arm thing was such a pain in the ass at times, but I’m glad it’s at least documented by players. It also seems like it shouldn’t be *that* hard for one of us to fix, even if the solution is something simplistic like distributing weapons in a fixed order (so that it’s deterministic behaviour) across the mech’s arm and torso slots. Even just alternating between arms would prevent stuff like this absolute horror from happening: https://hachyderm.io/@MHLoppy/116308370578550343 Another thing to add to my to-do list and then never get around to I guess 😛

Re: the amount of stuff behind the scenes, yeah I was shocked to see the level of detail in the game data when I was looking through it. If I had to put money on it I’d guess most of it actually ended up never being used, given that even a key system like heat gets completely ignored in MC1 (and then in MC2 got a simplified implementation only). At the same time I wouldn’t be shocked if they actually did use a few of the stats in ways that are hard to notice during moment-to-moment gameplay.

Edit/addendum: that is, Battletech applies damage first to armour, then any damage that hits internal structure rolls for a critical hit that can do all kinds of things. (And there’s a 1/36 chance for a lucky through-armour crit check, for those golden bb FASA Moments we love so much). Code I don’t know but Mechcommander seems surprisingly faithful behind the scenes from some of the stuff in https://github.com/oseparovic/MCGExtracted/blob/master/MISSION.FST/gamesys.fit and all the internal components listed in the csv, and the tonnage/crit breakdowns in mech defines, assuming they actually do anything in game.

So I’m assuming that behind the scenes hits that only damage armour and hits that damage internals are handled somewhat differently.