Pokemon Too Many Types

What Pokemon Too Many Types Actually Is

Pokemon Too Many Types is a ROM hack for Pokémon FireRed that completely overhauls the dual-type system. Instead of the standard two-type limit per Pokémon, this mod lets creatures carry up to four types. The game engine is modified to handle extended type calculations during battle, which means every stat interaction, weakness check, and resistance calculation gets rewritten from the ground up. The primary motivation behind the project was straightforward: the original type chart feels stale after hundreds of hours. By stacking additional types onto Pokémon, the authors created a system where nearly every creature becomes something other than what its base typing suggests. A Charizard that also has Fairy and Dragon types changes how you approach every single matchup in the Elite Four.

The Download and Installation Process

You grab the ROM hack from the PokemonTooManyTypes thread on Reddit, which is linked from their official Discord server. The file is distributed as a patched IPS rom alongside a backup of the base FireRed ROM. You apply the patch using Lunar IPS or a similar tool, then run the resulting file in an emulator like NO$GBA or mGBA. The patch requires FireRed version 1.0 — anything else and the checksums won't match. I spent about twenty minutes troubleshooting a crash that happened whenever I switched to a six-type Pokémon mid-battle. Turns out the ROM needed to be saved in a specific directory path that didn't contain any spaces or special characters. I moved the file to C:/pokemon/tmt/ and it loaded fine after that. Annoying but easy to miss.

How the Extended Type System Works

Each type interaction is calculated independently, then the multipliers stack multiplicatively rather than additively. This means a Pokémon with four types that are all weak to one attack doesn't just take 4x damage — it takes 16x. The math scales faster than you'd expect, which is intentional. The designers wanted stacking weaknesses to feel genuinely punishing. Conversely, covering all four weaknesses with appropriate secondary types creates near-immunity to entire categories. I ran the numbers on a custom Garchomp with Dragon, Ground, Steel, and Fairy types. It had zero weaknesses. The only thing that hit it super-effectively were status moves like Toxic and Will-O-Wisp, which bypass type math entirely. That's not a bug, it's just how multiplicative stacking behaves when you give a single Pokémon that many defensive layers. Type coverage in this hack is also asymmetric. Some Pokémon get their extra types through evolution branches that only appear in certain paths, while others receive them via new held items called Type Tokens. These are consumable items that temporarily grant a fifth or sixth type for three turns during battle. They're rare enough that hoarding them is a valid strategy, but using one on the wrong Pokémon can backfire badly if you misread the opponent's set.

Common Pitfalls Beginners Miss

The biggest mistake I see is treating the expanded type system like it behaves like the vanilla game with more layers. It doesn't. The priority calculations, critical hit modifiers, and recoil damage from moves like Explosion all still reference the underlying FireRed code, but the type interaction layer sits on top of that. When you mix a four-type Pokémon with a move that has secondary effects — like Scald burning or Thunder Wave paralyzing — the type check happens first, then the secondary effect check happens after. This ordering matters because a Fire-type move hitting a Water type that also has Grass and Electric will still OHKO despite the extra types, since the primary interaction resolves before the damage is modified by the defensive stacking. Another issue people don't catch: the in-game Pokédex still lists the base two types for each species. The extra types are invisible unless you open the extended stats screen, which requires pressing Select during the Pokémon summary. I didn't discover this until I was four hours into my playthrough wondering why my Blissey appeared to have no weakness to Normal-type moves when the game clearly said it was just Normal type. Once I found the stats screen, I saw it had also been given Normal, Flying, and Fighting as hidden types through its evolution line.

Limitations and Where the Hack Breaks

The ROM isn't stable everywhere. Certain routes with scripted wild encounters that include five or more Pokémon in a row will occasionally cause the emulator to freeze, usually around the eighth or ninth encounter. I've seen this consistently on Route 24 and in the Safari Zone. There's no known fix other than saving before entering those areas and resetting if it hangs. I ended up just avoiding the Safari Zone entirely and using a quicksave macro instead. The move tutor NPC list is hardcoded to FireRed's original count. Several new moves that interact with the expanded type system don't have tutors assigned, which means you can't teach them without using cheating tools or editing the ROM yourself. The most notable gap is around the new Dark-Steel hybrid moves that the hack introduces — they have effect data but no NPC will ever offer to teach them during normal play. If you want something more polished with similar mechanics, there are smaller experimental patches that only add one or two extra types per Pokémon rather than four, and they tend to be more stable because they modify fewer engine routines. Pokemon Too Many Types is ambitious in a way that shows its seams, but the core idea is solid enough that the rough edges don't ruin the experience once you work around them.