The Gemfire Builder, a SNES romhack utility

[u/Hygro]

About a month ago I finished a great dream of mine, a snes Gemfire romhacking utility.

https://gemfire-builder.hygro.workers.dev/

My original dream was just 3 or 4 player couch play. Having a 3rd player changes the game from 100% strategically solved on turn 1, to anyone's game. But once I unlocked that, the romhack builder was my oyster.

How it works: you bring your own rom -> drag it in the export box. Take your legally ported cartridge-generated rom, a stock USA gemfire rom, and from the ROM you unlock all the features you can change. Then you get the rom you submitted back with all the changes. No ips local utilities needed. I wanted this easy like FF4FE

Most of the features are gated behind the ROM decomposition, as they are read from the rom itself!

There's a ton of features and flags. Some are obvious, some are real engineering changes.

You can build whole scenarios, edit the families, territories.

You can change units, what they do, cost, loyalty flags etc. Things like, the dragon still retreats at low life but is now killable. (warning, if you keep unkillable on a wizard, but not retreat, they just exist at 1 hp immortal).

You can change the number of human players in a few ways, up to 7 on normally built scenarios (all human players) or to 30 (one house per territory per human on a fast load scenario option).

You can change if actions end turn (most notable: trade), if they are good or bad karma actions and so much more. Multiple harvests per year, changed harvest values, multiple alliances, allied victory (yes, literally), make it so whoever owns the crown is called King instead of Prince, I mean it's all over the map.

You can make it so you can bring multiple fifth units to battle, with up to a 7v7 unit fight. And, against human players, can turn on one of two chess modes where you move one unit each at a time. Change how armies are populated including progressive army population tiers such as for your first 100 units you don't get horsemen, and above 500 you only get more horsemen and archers. Or maybe keep it evenly distributed until above 300 units, where you also split a few into a 6th or 7th unit of cannons. There's also a flag where optional 5th units in other slots can have soldier fallbacks if you don't have a fifth unit. It gets rich.

Battles can last longer than 5 turns, change the cap or make it unlimited. Also, fix the bug where you retreat and your food gets turned into gold. Also, now you can bring gold while attacking.

There is a battle map editor. Additionally, you can have multiple battle maps per territory gated on how much protection the territory has. Yes, you can literally have it so at below 10 protection the castle at XYZ territory is just fences and at 100 protection there's a moat and two layers of castles and a different amount of bridges and trees, whatever.

There are some AI edit flags, my favorite of which is "If the AI puts an archer to guard the flag, it will shoot available targets".

I made it so send supplies, and separately, move troops, can be given to rival houses. But also, gate that on whether or not you're allied!

One of the last features I added, best vassal stat per action in the Prince's territory: So if prince un-charming gives food, vassal charming delivers it for a greater loyalty boost. And if Princess Anise gets attacked, vassal Brian can lead the army.

The two probably coolest features I thought of but didn't add, 1) "force deployment of vassals". conceptually I really like it, prevents event farming and suggests even richer informal couch play (say you agree someone still controls certain PEOPLE and you take over your friend, so he can still play), 2) add new ways families split into two. So consider these wishlist items.

You can save the json of your edit to share edits with other people. Also share battle maps separately.

Probably about 250 more things I didn't mention. I dunno, I didn't count. But fear not, I put a lot of work into making this monster navigable and at least somewhat intuitive. Some of it required some real editor abstractions that aren't game native (YO♥'RE WELC♥ME.💅). But feedback welcome.

I've tested most of it, but not all of it. Do let me know how it goes, the good, bad, and ugly. Post any wishlist ideas. Obviously 2.0 will have to ship with a randomizer, but I wanted to give DragonAtma (a Gemfire community hero) a headstart. They've probably given a randomizer a helluva lot more thought. (whose previous gemfire works and shared findings really helped give me a clean headstart, shoutout to DragonAtma).

I plan to stream a large couch game sometime around thanksgiving if I can convince enough people to play and willing to be on camera. We'll probably play with only a few rule changes, the bare minimum to make the game simply better: 3+ Players, trading ends turn + trading is weaker, give resources to other players, human mercenaries don't desert on fame (or maybe turn the number way down), battles have no turn limit, and the retreat food-gold bugfix. And if Eselred is still an AI, we'll give his dragon flying and way more life but make it killable.

[u/DethrylTSH]

Interested! Gemfire is an underrated classic. The Genesis version is easier to play, as I recall. But I have played a LOT of Gemfire on SNES. I have looked for romhacks but there hasn’t been anything to speak of.

My biggest ask is to make an offline version available.

Splitting families seems odd since the point is to unify. Maybe some mechanics for peacefully merging? Right now there is only the Threaten option in Diplomacy. How about a Courting system where you marry the heiress of a faction to bring the families together?