Pokémon Infinite Fusion Randomizer Mode: Complete Setup Guide

Want to know how to turn on the Pokémon Infinite Fusion randomizer? The game has a full randomizer built right in, and every new run can shuffle wild Pokémon, trainers, gym leaders, gym types, and even items based on settings you pick yourself. The catch that surprises most players is this: the randomize option only appears when you start a new game if you already have an existing save file, and once a run is randomized, it is permanent. No NPC can undo it. This guide walks through the complete setup, every option explained in plain language, recommended presets for a first randomized run, and the traps that end runs early.

Quick note: pokemon-infinitefusions.site is an unofficial fan guide. We are not affiliated with Nintendo, Game Freak, or the creators of Pokémon Infinite Fusion. Game version covered: 6.7.2. Randomizer details come from the community wiki; small details can change between versions.

Pokémon Infinite Fusion Randomizer: What It Actually Changes in Your Run

The Infinite Fusion randomizer is not a ROM patch or a third-party tool. It is a built-in feature of the game itself that replaces the Pokémon you would normally encounter with different ones. The system works by comparing base stat totals. Every Pokémon has a base stat total, which is the sum of its six stats. When the randomizer needs a replacement, it picks a Pokémon whose base stat total falls within a chosen range of the original.

A concrete example helps here. Rattata has a base stat total of 253. If your randomness range is set to 50, the randomizer can replace Rattata with any Pokémon whose base stat total sits between 203 and 303. Early-route weaklings stay roughly weak, and late-game powerhouses stay roughly powerful, unless you crank the randomness range so high that anything can become anything.

Because replacement is based on stats rather than species, randomized runs keep a sensible power curve by default. You will not normally run into a legendary on Route 1 with balanced settings. That changes completely with the Insane preset or the Allow legendaries toggle, both of which are explained below. This stat-based design is also why fusion balance holds up: fusions inherit stats from their parts, so a fused replacement stays in roughly the same league as what it replaced.

Randomization touches more than wild encounters. Separate toggles cover trainers, gym leaders, gym types, starters, static encounters, gift Pokémon, items, and TMs. Each system can be randomized on its own or left untouched, so two players can play the same “randomized” mode and have completely different experiences.

How to Turn On the Pokémon Infinite Fusion Randomizer

There are two ways to start a randomized run, and which one you use depends on whether the run has already begun.

Starting a new randomized run

When you choose New Game from the title screen, the game normally asks you to pick a mode: Classic, Modern, Randomized, or Special, plus a difficulty of Easy, Normal, or Hard. The Randomized option only shows up if you already have an existing save file on your system. This is deliberate. The developers want players to finish a Classic run first, and there is a practical reason for it: Classic mode has more community custom sprites and some rewards and events that are unavailable in randomized mode.

So if you boot up the game for the first time and the randomizer option is missing, that is not a bug. If you have not installed it yet, download Pokémon Infinite Fusion first, then play through a Classic run, or at least create a save file, and the option appears on your next New Game. When you pick Randomized, the game walks you through every settings screen covered in this guide before the run begins.

Randomizing an in-progress run with the Update Man

Already mid-run and regretting your boring Classic encounter tables? Talk to the Update Man. He wears a black suit and stands in every Pokémon Center, often upstairs. He can randomize an existing save or change the randomizer settings of a run you already randomized.

Read this twice before you talk to him: randomization is permanent. The Update Man cannot un-randomize your game. If you randomized on Insane and hate it, he can only randomize you again with different settings; he can never restore the original encounter tables. This is the single most common randomizer regret players report, so decide on your settings before you commit.

One more Update Man quirk: when he randomizes an in-progress run, the encounter tables apply going forward. Your already-caught team stays exactly as it is. If you are doing your first playthrough and want the full randomized experience, start fresh instead of updating a half-finished save.

Understanding the Randomness Degree

The randomness degree is the master dial of the randomizer. It sets how wide the base stat total range can be when the game picks replacements. A degree of 0 means replacements must have exactly the same base stat total, while 500 means essentially anything can become anything. You set this degree separately for wild Pokémon and trainer Pokémon, so your route encounters can be wild and unpredictable while gym teams stay tame, or the other way around.

The game ships with four presets. Memorize these, because they define what the community means when it says a run was “on Balanced” or “on Insane”:

• Balanced: degree 0 for trainer Pokémon, or for wild Pokémon when Fuse Everything is on. Wild Pokémon without Fuse Everything use degree 25. This is the closest thing to a sane run. Replacements are near-equal in strength to the originals.
• Moderate: degree 50 for both wild and trainer Pokémon. A middle ground where you will regularly see surprising replacements, but the overall power curve of the region stays intact.
• Insane: degree 300 for both wild and trainer Pokémon. At this point base stat totals barely constrain anything. Expect chaos: endgame threats on early routes, gym leaders with teams that make no thematic sense, and runs that can end in the first hour.
• Custom: any value from 0 to 500 for wild and trainers independently. For players who want, say, wild encounters at 100 and trainer teams at 0, or anything in between.

For context, remember the Rattata example: with degree 50, Rattata (base stat total 253) can become anything between 203 and 303. With degree 300, that same Rattata can become almost anything in the game. The presets also interact with the wild options below, so a Balanced run with Fuse Everything on (degree 0 for wild) still gives you fusions everywhere, just fusions of roughly equal strength to what the route normally holds.

Every Wild Pokémon Option, Explained

Wild encounters have the most settings of any randomizer category. Here is what each one does, in the order the game presents them.

Randomize wild encounters

The master switch. Turn it off and every other wild setting is irrelevant; routes keep their normal encounters. Turn it on and the settings below take over. You can randomize wild Pokémon while leaving every trainer in the game untouched, which many players prefer for a first randomized run.

Type: Global or Area

This controls how replacements are mapped. Global applies one-to-one Pokédex mapping: every instance of a species, everywhere in the game, becomes the same replacement species. If Rattata becomes Pidgey on Route 1, Rattata is Pidgey in every route, cave, and patch of grass in Kanto and Johto.

Area randomizes per route instead. The Rattata on Route 1 might become a Pidgey while the Rattata in Viridian Forest becomes something else entirely. Area mode makes every route feel like a fresh surprise, while Global mode rewards learning the mapping. If you catch the replacement species once, Global lets you predict where to find more of it, which matters for hunting specific fusions. Our fusion tool shows you exactly what any fusion looks like and what it can do, so you can decide which mappings are actually worth chasing.

Custom sprites only

A toggle that limits replacements to Pokémon with community-made custom sprites. The Infinite Fusion community has created custom sprites for a large portion of fusions, and some players prefer their randomized run to only contain fusions that have this artwork. Keep in mind that Classic mode has more custom sprites overall, so this toggle gives you a smaller pool in randomized mode than you might expect.

Allow legendaries

Off by default, and the default is the sane choice. With Allow legendaries off, only legendary encounters become other legendaries. A normal wild encounter will never turn into a legendary, so early routes stay fair. With Allow legendaries on, any wild encounter can become a legendary. Combined with a high randomness degree, this is how players end up staring down a Mewtwo in the first patch of grass and watching their run end before it starts.

Starter Pokémon options

Three choices for your starting Pokémon. 1st Stage randomizes the starters but limits them to first-stage Pokémon, so you still start with something unevolved and roughly starter-strength. Any opens the pool to fully evolved Pokémon, which can hand you something absurdly strong (or hilariously weak) at level 5. Off keeps the normal starters. The 1st Stage option is the community favorite for runs that feel fresh without breaking the early game.

Static encounters and gift Pokémon

Separate toggles cover static encounters, which include scripted one-time encounters such as legendaries, and gift Pokémon, the ones NPCs hand you. Randomizing statics shuffles which legendary waits at the end of each storyline, which is a big part of the appeal for veteran players. Gift Pokémon randomization changes the free team members the story gives you, so plan around the possibility that your usual freebies will not be there.

Fuse everything

This forces every wild Pokémon to be a fusion. It is the closest the randomizer gets to the Special mode experience (which makes all wild encounters fusions by default) while keeping the rest of the game randomized your way. Note the interaction with presets: on Balanced, wild Pokémon use degree 0 when Fuse Everything is on, meaning every wild fusion will be roughly as strong as the unfused Pokémon it replaced. That makes Balanced plus Fuse Everything one of the most popular settings combinations in the community.

Trainer, Gym Leader, and Gym Type Options

Trainer randomization is where runs get genuinely unpredictable, because you cannot see the enemy team until the battle starts. The game splits this into two systems with very different behavior, and the difference matters.

Regular trainers stay fixed once randomized

When you enable trainer randomization, all non-gym trainers get randomized teams. Here is the important part: regular trainers are randomized once, at game start, and they keep those teams on rematch. If the Youngster on Route 3 leads with something terrifying, he will lead with the same terrifying thing every time you rematch him. This lets you scout and prepare. Losing to a regular trainer costs you nothing strategically, because you can walk back in with the counter.

Gym trainers re-randomize before every battle

Gym trainers and gym leaders behave differently on purpose. Their teams are randomized before each battle, and if you lose and rematch, they get new teams. This is an anti-soft-lock design. In a randomized run, a fixed gym team could theoretically roll something you have no answer for at that point in the game, and you would be stuck forever. Re-rolling on rematch guarantees that a loss always gives you a fresh, potentially easier matchup. It also means you cannot scout a gym leader’s team by losing on purpose and coming back prepared, because the team will be different.

Gym leaders and gym types

The gym randomization option shuffles gym leaders and their teams, with the same re-roll-on-rematch behavior. A Custom sprites only toggle applies here too, limiting gym teams to fusions with community artwork.

The wildest gym option is Gym types: every gym gets assigned a random type. Brock’s Rock gym might become a Water gym or a Ghost gym. You find out the type by talking to the man standing at each gym’s entrance before you challenge it, and the gym leader’s background changes to match the assigned type as a visual hint. A Rerandomize each battle toggle decides whether the gym type also shuffles between attempts. With it on, the gym you scouted as a Water gym could be a Fighting gym on your second try, so check the entrance man every time.

Item and TM Randomization

Item randomization is the sleeper setting that changes how the whole game feels. It does not touch your team at all, but it rewrites the economy: what you find, what you can buy, and what TMs you have access to.

What can be randomized

• Found items: the contents of item balls scattered around the world.
• Found TMs: TMs picked up from the ground or in item balls.
• Given items: items handed to you as rewards.
• Given TMs: TMs awarded by NPCs or events.
• Shop items: what the Poké Marts stock.
• Trainer held items: what randomized trainers carry into battle.

How item rolls work

Item balls are rolled when you pick them up. The contents are decided at the moment you grab the ball, which leads to the classic randomizer trick: save before picking up an item ball, and reset the game if you do not like the roll. Each reload re-rolls the contents. Players hunting for specific TMs or rare items use this constantly.

What is excluded, and the duplicate TM problem

Not everything is on the table. Key items, NPC-given items, Poké Balls, and DNA Splicers are excluded from randomization. The game protects progression items and the core fusion mechanic, so you will never be soft-locked out of fusing because a shop stopped selling Splicers.

Two quirks to know about. First, duplicate TMs are possible: you can find the same TM in multiple locations, which means some TMs you would normally get are simply missing from your run. Second, unimplemented items can appear: the item pool includes some items that do nothing in the current version. Finding a useless item in a spot that normally holds something great is part of the randomized experience. Budget your expectations, and your money, accordingly.

Recommended Settings for Your First Randomized Run

If this is your first time with the Pokémon Infinite Fusion randomizer, resist the urge to turn everything on at once. A full-chaos setup sounds fun until a randomized gym leader sweeps your team twenty minutes in and you realize the run was unwinnable from the start. Start conservative, learn how the systems feel, then crank things up on your second run.

• Randomness degree: Balanced for both wild and trainer Pokémon. Replacements stay near the originals’ strength, so the region’s power curve survives.
• Wild encounters: on, set to Area. Every route feels new without anything becoming unfair.
• Trainers: on. Regular trainers keep their randomized teams on rematch, so you can scout and adapt.
• Gym types: off for run one. Randomized gym types are a great twist, but learn the base gyms first.
• Allow legendaries: off. Keep early routes fair.
• Starters: 1st Stage. Fresh starters without the risk of a level 5 fully evolved monster.
• Fuse everything: optional, and highly recommended. On Balanced it uses degree 0 for wild encounters, so every wild Pokémon is a fusion of roughly appropriate strength. It is the most “Infinite Fusion” way to play the randomizer.
• Items and TMs: off for run one. Item randomization is fun, but missing key TMs can quietly ruin a run for a beginner.

Once you are comfortable, the classic “second run” setup is Moderate degree, gym types on, and items on. That combination keeps runs winnable while making almost nothing predictable. Plan your team around the coverage you actually find: our team builder helps you spot type-coverage holes, and the Infinite Fusion dex is useful for tracking which randomized species you have already caught.

Randomizer vs Classic, Modern, and Special Mode

The randomizer is one of four ways to play, and picking the right one matters. Here is how they compare.

• Classic Mode: the FireRed-style experience. Encounters match the original games, with the most community custom sprites and access to every reward and event. Play this first. It is also the mode that unlocks the randomizer option for future runs.
• Modern Mode: the same regions, but encounters are shuffled to later-generation Pokémon in fixed (not random) locations. Trainers carry different teams, often including fusions, and gym leaders change type specialties. Harder than Classic, but fully predictable once you learn it.
• Randomized Mode: this guide. You choose exactly which systems get shuffled and how wild the replacements can be. Every run is different, and difficulty depends entirely on your settings.
• Special Mode: every wild encounter is a fusion, with no other randomization. It is the simplest way to get fusion chaos without touching any settings screens.

One choice applies to all four modes: difficulty. You pick Easy, Normal, or Hard when the run starts, and you cannot change it later. For a first randomized run, Normal is the honest pick. Hard plus a high randomness degree is a combination that ends a lot of runs before the second gym.

Randomizer Traps That End Runs Early

Most failed randomized runs do not fail because of bad luck. They fail because of one of these traps.

• The permanence trap. The Update Man cannot un-randomize your game. Every settings choice is final the moment you confirm it. Screenshot your settings screen before you start, so you at least know what you picked.
• The legendary-on-Route-1 trap. Allow legendaries plus a high randomness degree can put an endgame threat in the first patch of grass. If you want legendaries in the pool, keep the degree at Moderate or below.
• The gym-scouting trap. Regular trainers keep their teams, so scouting works on routes. Gym teams re-roll on rematch, so scouting does not work in gyms. Do not waste a sacrifice lead trying to learn a gym leader’s team; it will be different next attempt.
• The un-scouted gym type trap. With randomized gym types on, always talk to the man at the gym entrance before challenging it. Walking into a gym blind when its type was shuffled is how teams get wiped.
• The missing-TM trap. Item randomization can scatter duplicates of one TM across the map while the TM you actually needed never appears. If your run depends on a specific TM, use the save-and-reset trick on item balls, and keep a backup plan in your movesets.
• The no-backup trap. Randomized runs have more ways to go wrong than Classic runs. Keep a rotating set of save files, especially before gyms and before talking to the Update Man. Our interactive map can help you plan routes and check what each area normally holds, which makes scouting randomized encounters much faster.

Frequently Asked Questions

• Can the Update Man un-randomize my game? No. Randomization is permanent. He can randomize an already-randomized run again with different settings, but he can never restore the original encounter tables.
• Why is the Randomized option missing from my New Game menu? It only appears if you already have an existing save file. Create a save, then start a new game, and the option shows up.
• Does randomizing change the Pokémon I already caught? No. Your caught team stays exactly as it is. Randomization applies to encounters and trainers going forward.
• Can a legendary really appear on Route 1? Only if you enable Allow legendaries and use a high randomness degree. On Balanced with legendaries off, early routes stay fair.
• Do gym leaders keep their randomized teams if I lose? No. Gym trainers and leaders re-roll their teams before every battle, which is deliberate anti-soft-lock design. Regular trainers keep the same randomized team on rematch.
• Will I miss content in a randomized run? Some Classic-mode rewards and events are unavailable in randomized mode, and the custom-sprite pool is smaller than in Classic. The story, regions, and fusion mechanics are all intact.
• Does the randomizer change fusions I make myself? No. Fusions you create with DNA Splicers follow the normal fusion rules regardless of your randomizer settings. If you want to preview a fusion before committing Splicers, check it in our fusion calculator first.

Your First Randomized Run Starts With Balanced Settings

The Pokémon Infinite Fusion randomizer is one of the best-implemented randomizers in any fan game, precisely because it lets you tune the chaos instead of just unleashing it. Start on Balanced with wild encounters and trainers randomized, keep legendaries off, and learn the systems before you touch Insane. For the full reference on every toggle, the Fandom wiki’s Randomized Mode page documents each option, and the official changelog tracks what each version changed. Now go break Kanto in the most interesting way possible.