Pokemon Emerald Imperium ROM

Pokemon Emerald Imperium is a GBA ROM Hack by iriv24 based on Pokemon Emerald. It was last updated on August 01, 2025.

Description

Pokemon Emerald Imperium is a QoL / difficulty Emerald hack with a slightly altered story that is fully beatable through the Champion battle (and has a little post-game). I’ve also added some characters from Gen 4, namely Dawn as an additional rival throughout the game, all the Gym Leaders as optional trainers to fight (except Roark, he’s mandatory), and more!

Other notable features and additions include a built-in randomizer, a couple of difficulty options (just Easy and Normal for now, maybe I’ll add a Hard mode in the future or something), several new Mega evolutions, including all the Sinnoh starters, and a whole lot of balance changes to various mons. It’s also got every QoL / feature branch under the sun in there somewhere, so I won’t list them all here.

I’ll probably come back and edit this message at some point to include links to the docs and other things that I’m still polishing up, which will list everything in excruciating detail. I’m sure this game won’t be many folks’ cup of tea around these parts, but I still wanted to post it because I am happy with myself for sticking with this for so long, making the game that I wanted to make, and getting it to a place where I am comfortable sharing it with others.

Also as you will see in the credits, many of your guys’ assets, features, and ideas are in the game somewhere, and I definitely would not have stuck with this project for so long if it weren’t for the homies here, so it is definitely a community hack in that sense.

Features

• Almost all Pokemon from Gens 1 – 9 available
• Modern battle engine
• Mega Evolutions, featuring new custom Megas added for several Pokemon including Gen 4 starters and several Gigantamax forms converted to Megas
• Several Gen 4 characters added, including Dawn as an additional rival, all the Gym Leaders, and more!
• Increased difficulty of trainer battles, with focus on Gym Leaders/Elite 4, Rivals, Team Aqua/Magma battles, route Mini Bosses, and optional Mini Bosses
• Several other optional Boss Trainer battles (with hopefully good enough rewards to incentivize the player to actually want to do the battles) 
• Configurable Minimal Grinding Mode
• Built in Difficulty Modes: just Easy and Normal for now
• Built in Randomizer with configurations for species and ability randomization
• Built in Level Caps
• DexNav
• Balance updates for Pokemon to match RR, which includes type-changes, stat updates, ability updates, learnset updates, etc. The goal for this was to be able to reuse the online RR dex and the RR damage calculator.
• Small story tweaks, mostly with the goal of lining up difficult battles
• Not needing to teach HMs to use them, and they are forgettable if taught
• Reusable TMs
• PokeVial with infinite uses to heal your party from anywhere
• Access to the PC from anywhere
• Stat Editor (for EVs and IVs) given in Mauville
• Toggleable following Pokemon, Auto Run. and Infinite Repel
• Hold R to speed through NPC dialogue
• Option to relearn level-up moves and egg-moves for a Pokemon in the party menu
• Move-tutor moves converted to TMs so they can be taught anywhere, no more move tutors in game
• Item care packages
• Ability Capsules and Ability Patches to easily change between abilities for a Pokemon
• 2nd Nurse in every Pokemon Center who can:

  • Change Pokemon’s natures

  • Swap genders for Pokemon with gender-specific evolutions

  • Set Pokemon directly to the Level Cap

Known Bugs

• Some of the color palettes of the follower Pokemon have issues being on screen at the same time as some of the custom overworld sprites. The example I have come across is Charmander or Gardenia’s palette not loading correctly, depending on which one is loaded on screen first. In theory, one specific follower probably causes the same issue for each of the custom overworld objects, so if you find another example of it please let me know!
• Some shiny overworld Pokemon do not display correctly (you can fix this easily by opening the party menu, bag, or some other menu)
• While not technically a known bug, my goal was to match the data for each Pokemon found in https://dex.radicalred.net/, and I am sure I missed some things (especially learnset data), so please report any inconsistencies that are not documented as intentional changes!
• Pomeg Berry merchant and some other mart workers can crash the game on MyBoy emulator.

Changelog

V1.3

Full Changelog here

V1.2

New Additions

• Added Battle Bond as Greninja’s 2nd ability, so Ash-Greninja is now available to the player
• Added Beast Balls to Lilycove Department Store
• Added Big Root to Lavaridge Herb Shop
• Added Wild Encounters to the areas where the Regis and the Sinnoh Lake Trio are found
• Added cheat code “MaxMoney”, which maxes the player’s money
• Added messages to indicate when the player’s level cap has increased
• Added the ability to run away from wild pokemon by tapping the “R” button – by yyatsuta
• Set the roamers’ “seen” flags during the event that spawns them so the player can immediately start tracking them in the Pokedex without needing the “CaughtAll” cheat
• Added several new optional trainers in Mossdeep City and Sootopolis City, to commemorate the first players to beat the game
• Added Nurses (2nd Nurse from Pokemon Centers) to Seafloor Cavern and Magma Hideout so the player won’t have to run back as often
• Added a patch of grass with Wild Encounters to Rustboro City, which notably contains Shroomish! See the Encounters Document for the full encounter table
• Gave Gift Pokemon a 1/600 chance to be shiny
• Added a Move Deleter to Slateport City, replaced former (retired) Name Rater
• Added an NPC that gives Arceus Plates in Sootopolis City
  
  • Functions the same as the NPC who gives Silvally Memories
  • Starting Care Package Pixie Plate and Iron Plate replaced with Fairy Feather and Steel Feather, respectively
• Added TM for Dark Hole into Steven’s Cave (Meteor Falls, post game)
• TMs in shops now display the name of the TM while purchasing
• Added Red and Blue Orbs to Mt. Pyre Summit post Sootopolis-Legendary events
• Added NPC that gives form-changing items for Dialga, Palkia, and Giratina to Sootopolis
  
  • Those 3 Legendaries are still only available in the randomizer
• Added NPCs that give form-changing items for Zacian and Zamazenta to Sootopolis
  
  • Those 2 Legendaries are still only available in the randomizer
• Added NPC that gives form-changing item for Zygarde
  
  • Still only available in the randomizer
• Added NPCs that give fusion items for Calyrex, Necrozma, and Kyurem to Devon Corporation
  
  • Need both Pokemon to perform the Fusion (example: both need Kyurem and Zekrom to get Kyurem-Black)
  • Only Kyurem and Calyrex are available in before post-game. The rest of the involved Legendaries are post-game only
  • Need 8 Badges to receive these items
• Added Sheer Force as a Hidden Ability for Mega Charizard Y
  
  • To get a Megas respective Hidden Ability, the base form Pokemon needs to have its Hidden Ability. This is not new functionality, just an explanation
• Added Sand Force as a Hidden Ability for Mega Tyranitar
• Added functionality to “Use” Poke Balls (and other Balls in the Ball Pocket) to change which Ball a Pokemon is inside – developed by Lunos, merged by yyatsuta
  
  • Does not consume a Ball to do so
• Added Dusknoirite to the Mega Stones given by the “Mega” cheat code

Changes

• Adjusted several Wild Encounter tables, for specifics please check the Encounters Document
• Changed “Zen Mode” on Darmanitan to activate at full health to match what is done in RR – by yyatsuta
• Removed Crashy the Bard (NPC that can crash the game in Mauville Pokemon Center) and replaced with an NPC that gives Costume Pikachus in exchange for Yellow Shards
• Changed Tate’s Kangaskhan Ability to Inner Focus
• The “Set Pokemon to Level Cap” will now only be available once the player has met the Move Relearner in Dewford Town
  
  • This was done to avoid player’s immediately going to the level cap and skipping level-up moves, which seemingly happened a lot 
• Changed Tandemaus evolution method to no longer require leveling up in battle
• Change scripts to skip the Wally Catching Tutorial – by yyatsuta
• Change scripts to skip the PokeNav Match Call tutorial – by yyatsuta
• Switched locations of a few early game TMs
  
  • Former Bullet Seed TM location now gives Bug Bite
  • Former Bug Bite TM location now gives Stomping Tantrum
  • Former Stomping Tantrum TM location now give Bullet Seed
• Elite Four Phoebe’s Fezandipiti changed from a Physical Attack set to a Special Attack Set
  
  • This was done to accommodate the stat changes made to Fezandipiti by RR, where its Special Attack is higher than its Attack 
• Zorua and Hisuian Zorua are no longer found on the same floor of Granite Cave so that they can both be DexNav’ed 
• Beauty Jessica’s Magnezone’s Stealth Rocks replaced with Body Press
• Crasher Wake’s Gyarados’ Bounce replaced with Ice Fang
• Champion Wallace’s Empoleon’s Brick Break replaced with Protect
• Champion Steven’s Empoleon’s moveset changed to Toxic, Flash Cannon, Flip Turn, Roost
• Updated Norman’s text regarding the Trick House to make it more apparent that three floors must be completed before challenging the gym
• Increased DexNav timeout from 15 seconds to 15 minutes
  
  • You can cancel a search by pressing “L” or “Start”, which will not break a DexNav chain
• Removed limitations for changing IVs in non-MGM once the Stat Editor is obtained
• Allowed Hoopa-Unbound to be reverted back to normal form using the Prison Bottle
• When a Pokemon reaches red HP, the beep will now only play 4 times and then stop instead of playing continuously – convincing iriv24 to add to game and implemented by yyatsuta
• Removed Secret Power from all learnsets
• Made Shaymin form change with Gracidea a “normal” form change
  
  • You can now change back and forth between Shaymin and Shaymin-Sky without worrying about it reverting due to Frostbite or time of day
• Changed Meltan’s Ability from Magnet Pull to Transistor
• Elite 4 will now scale to level 100 after you become the Champion
• Updated Cynthia Encounter music and Victory music
• Removed all forms of Zygarde from the randomizer except for Zygarde 10 Aura Break
• Changed Mega Sableye’s first and second Ability to Prankster
• Changed Mega Absol’s second ability to Sharpness
• Changed Abomasnow’s second ability to Slush Rush
• Changed Hatenna lines second ability to Magic Guard.
• Moved Harvest from Hidden Ability to second ability for Smoliv line
• Moves Corrosion from Hidden Ability to second ability for Glimmet line
• Some Mythicals have been removed from Wild Encounters, as they are now given as Gift Pokemon from optional trainer battles in Sootopolis City
• Changed several important battle reward item locations
  
  • Metronome – Now given by Fantina instead of Trick House
  • Expert Belt – Now given by Maylene instead of Fantina
  • Focus Sash – Now given by Crasher Wake instead of Daisuke
  • Loaded Dice – Now given by Daisuke instead of Dawn on Route 111
  • Protective Pads – Now given by Daisuke instead of Dawn in Lilycove
  • Eject Button – Now given by Volkner instead of Dawn in Lilycove
• Remove Metal Coat from wild Bronzor, Magnemite, and Beldum
• Make Infinite Repel prevent encounters from Rock Smash
• Make Meloetta only change forms when using Relic Song, will not revert outside of battle to match RR

Bug Fixes

• Fixed Winona not giving the TM for Acrobatics after defeating her
• Fixed DexNav Search Levels to properly increase and affect the chance of getting a Pokemon with a Hidden Ability or Egg Move – fix found by yyatsuta
• Fixed Rattatas evolution level to match RR data
• Fixed Swinub and Piloswine evolution methods to match RR data
• Fixed Ghimmighoul-Roaming being unable to evolve
• Fixed Pineco evolution level to match RR
• Fixed Basculin evolution method
  
  • Red Stripe, White Stripe, and Blue Stripe can now all evolve into Basculegion at level 44, evolution depends on Gender
• Fix Snover abilities to match RR
• Fixed (hopefully) all Pokemon learnsets to match those of Radical Red – special thanks to hzla for writing the script to make this possible
• Fixed (hopefully) all unintentional stat discrepancies to match those of Radical Red – special thanks to hzla for writing the script to make this possible
• Fixed some potential crashes that could happen in the Safari Zone on some emulators
• Fixed Rival potentially disappearing if the player lost the Rival battle in Rustboro City which could result in softlocking the player at level 20
• Fixed battle style getting stuck on “Shift” in Normal Mode if the player changed difficulties between runs
• Fixed missing dot for “Key Items” in player’s Bag – by yyatsuta
• Fixed Explosion not halving the Defense of the Pokemon taking damage
• Fixed typo in Hustle’s Ability description
• Updated list of moves that benefit from “Striker” and “Sharpness” Ability – special thanks to hzla for writing the script to make this possible
  
  • Thunderous Kick is boosted by Striker here and NOT in RR
• Fixed Gender Swapping functionality not working Burmy variants
• Added a rock to the water in Route 124 to prevent the player from getting outside the map into Lilycove
• Fixed shiny follower Pokemon and overworld Pokemon sometimes appearing as a Substitute or incorrect sprite
• Fixed typing of Raging Bull to not always be Fighting Type for Tauros – by yyatsuta
• Fixed weight of Mega forms converted from Gigantamax forms to not be 0
• Fixed a crash that could happen if Pursuit caught a Pokemon switching out
• Fixed Liquid Voice not giving a 20% boost to Sound moves, as well as moves not displaying as Water type in the summary screen
• Fixed Ability Transistor to give 50% boost instead of 30% to match RR
• Fixed Corrosion not making Poison moves hit Steel type Pokemon to match RR
• Fixed the Gift Beldum from Steven turning into a Squirtle
• Fixed Cheat Codes re-entering the most recent Cheat Code if nothing was entered
• Fixed Roamers not having perfect IVs in MGM
• Fixed Quick Feet Ability to give 2x speed instead of 1.5x to match RR
• Fixed typo in “Verdanturf”
• Fixed Iron Fist and Striker Abilities to now give 30% boosts instead of 20% to match RR
• Fixed Manectric Hidden Ability not being Intimidate
• Fixed Reveal Glass not working on Enamorus
• Fixed Protean/Libero changing Pokemon to the type of its 4th move when facing Boss Trainers
• Fixed exploits where players could get Galarian-Moltres and Lugia earlier than intended
• Fixed underleveled Bug Catcher on Route 123
• Fixed Leek item not matching functionality with RR – caught by yyatsuta, twice
• Fixed Birch sprite missing when he gives you Aurora Ticket in post-game
• Fixed a bug that would cause a Pokemon using a recoil move to take damage, even if the move was absorbed.(Example: using Flare Blitz into a Pokemon with Flash Fire will no longer deal recoil)
• Fix Razor Shell not being a high-crit move to match RR
• Fix Roamers having 0 HP and bugging out when encountering them for a 2nd time  – by yyatsuta

Ai Changes

• Fixed AI not accounting for its Pokemon having Parental Bond or ORAORAORAORA!
• Fixed AI trying to use weather setting moves when a Pokemon with Cloud 9 is on the field
• Adjusted AI behavior when determining when to throw in an “Absorb” mon (will no longer swap to an “Absorb”mon if the AI can OHKO the player or if they have stat raises)
  
  • An “Absorb” mon is one with an ability that can absorb a move, think Water Absorb throwing into a water-type move for example
• Adjust how the AI behaves when the player has the move “Encore” (AI discouraged to go for set up when the player has Encore)
• Improved AI battle mechanics when the user is holding a resist berry. AI can now see 2HKO through resist berries.
• Improved AI switching mechanics. (For example: Pokemon with Choice items will now look at their last used move rather than the last move used period when determining when to switch)
• Adjusted rolls used for AI damage calculations in the following scenarios:
  
  • AI will use highest rolls when calculating the damage it can do to the player when picking a move for the Pokemon on the field
  • AI will use the highest rolls when calculating the damage the player can do to it when determining if it the AI should go for a setup move
  • AI will use the median rolls when calculating the damage it can do the the player when choosing a switch-in candidate
  • AI will use the median rolls when calculating the damage the player can do to it in all scenarios besides going for setup moves
  • This was all done in an effort to make the AI play more aggressively in certain scenarios and be slightly more discouraged to go for setup moves without completely reworking the AI’s scoring system

V1.1

Additions

• Damp Rocks, Icy Rocks, and Smooth Rocks given as part of Granite Cave care package
• Light Clay added to care package given on Route 110
  • Also available for purchase in Mauville City Mart
• Added overworld rain to route 102 to allow earlier access to Goodra 
• Added Shiny Charm to starting care package from Professor Birch
• For existing saves to not start a new game, there in an NPC in a house in Olddale Town that will give you the Shiny Charm if you do not already have one.
• Added cheat code “ShinyS” to guarantee shiny starters at the beginning of the game
  • Applies to randomized starters as well

Changes

• Removed EVs from Pokemon found before Wattson (only effects non-MGM)
• Removed Lets Go Eevee from the randomizer pool
• Swapped Mudbray and Phanpy encounter locations 
  • Mudbray now found on Route 117 Phanpy on Route 102

Bug fixes

• Fixed crashes involving Double Iron Bash and Mind Blown on some emulators
• Fixed crashes players could experience when buying Pomeg Berries from the man in Dewford Town and some vendors in Slateport City on some emulators
• Fixed crashes caused by the man giving starter eggs in Fallarbor Town on some emulators
• Fixed move compatibility on several pokemon including Pidgeot, Alakazam, Hisuian Samurott, Empoleon (lol), Aurorus, Electivire, Iron Bundle, Audino
• Fixed the move Diamond Storm (was physical, now is special)
• Fixed Swanna’s Hidden Ability still being Hydration (now is No Guard)
• Removed the need to use Flash in Granite Cave 
  • This should remove the “It’s too dark to find anything” text box that would appear when trying to use the Dexnav
• Fixed Scott’s dialogue in Petalburg
• Fixed Rockruff not being able to evolve into Lycanroc-dusk form
• Fixed shiny chaining with Dexnav allowing the player to encounter Pokemon above the current level cap
• Fixed Applin being unable to evolve into Dipplin

Useful Links

Pokecommunity

Discord

Documentation

Reddit