|Dubious Disc Locations
|Veilstone City — On the first floor of Galactic HQ, in a room containing a Scientist trainer. Only available after defeating Leader Candice in Snowpoint City.
|Route 225 — Across a pond southwest of the Battle Zone’s Survival Area. Requires HM03 Surf.
There are only two Dubious Discs you can get in Pokémon Platinum. The earliest one you can get is found in Team Galactic’s Headquarters in Veilstone City. But this can only be obtained after earning the Icicle Badge from Gym Leader Candice and visiting Lake Acuity.
The second Dubious Disc is located a bit past a pond on Route 225, which is available in the post-game.
Dubious Disc Locations
Location #1: Galactic HQ (Step-by-Step)
The first Dubious Disc you can get is in Team Galactic’s headquarters in Veilstone City. If you haven’t opened the Galactic Warehouse security door with Looker from the International Police, that’s your first step.
Then after defeating Leader Candice at the Snowpoint Gym, head to Mt. Acuity for a short chat with Commander Jupiter about some diabolical plans in Veilstone City.
When she leaves, Fly to Veilstone City to investigate.
If you try walking into the main Galactic HQ building in the northeastern sector of town, you will be denied entry.
Instead, speak with the Galactic Grunt standing in front of the building.
This will prompt the Grunt to run away.
Immediately afterward, Looker from the International Police will show up with the Storage Key the Grunt dropped while escaping.
Looker will then offer to open the HQ’s back door, which is found in the Galactic Warehouse on the other side of town.
There are quite a few level 40+ Grunt battles ahead, so heal your team at the Pokémon Center if needed, then start heading to the west.
Turn north at the street corner by the Department Store.
Turn eastward to move behind the Department Store, then head up the stairs to enter the Galactic Warehouse.
As soon as you enter, Looker will show up and use the Storage Key to open the security door.
Then he will take off down the stairs. Follow after him.
Head east through the hallway on the next floor, ignoring the corridor to the north.
At the first corner, you will come across one of several Galactic Grunts to battle.
None of these battles is particularly hard — the Grunts generally use the same Golbat, Houndour, and Stunky combos you’ve come to expect.
But they’re all around level 40 and can easily wear out your team if you’re not stocked on healing items.
Just defeat this Grunt and continue heading northeast.
A second Grunt is guarding the next corner, so defeat him and continue up the stairs.
The Grunt in the next room has no Pokémon and can’t battle you; so pass him and head up the opposite staircase.
In the northwest corner of the next room are a pair of yellow circles on the floor. These are warp tiles.
Stepping on one will teleport you to another one elsewhere in the building.
Fight the Galactic Grunt guarding the hallway, then step on the far left warp tile.
In the next room you’ll want to step on the next warp tile to continue.
Then head up the stairs in the next room.
You will find yourself in the middle of a hallway.
Head to the left end and step on the warp tile there.
Cross the hallway and go down the staircase to the east.
Then when you’re down the stairs, head west to enter the next room.
There is a Scientist trainer in here to battle, though it’s an optional fight.
But if you look toward the big metal table in the middle of the room, you’ll see a Poké Ball halfway obscured between two seats.
Examine this item to pick up the game’s first Dubious Disc.
Location #2: Route 225 (Step-by-Step)
The second Dubious Disc is located on Route 225. This is southwest of the Battle Zone’s Survival Area.
This area won’t be reachable until after you’ve entered the Pokémon League Hall of Fame and received the National Pokédex – so this Dubious Disc is only available in the post-game.
To get started, Fly to the Survival Area’s Pokémon Center and head west.
Then move northwest to enter Route 225.
Take the staircase to the far northwest.
Travel as far to the west as you can go, then circle down & go around the row of trees to head southeast.
Turn southward to climb the next staircase that leads onto a rocky platform.
Keep moving southward until you reach two staircases, then turn to climb up the left-hand staircase.
After that, head northwest past the Ace Trainer.
When you reach the small lake on the mountain, use Surf to cross it.
You will then see a Poké Ball item on the ground just below a staircase on the other side of the lake.
Pick up this Poké Ball to receive your second (and final) Dubious Disc.
Dubious Disc Details and Uses
The Dubious Disc is a held item that allows Porygon2 to evolve into Porygon-Z via trade.
To use it, first give the Dubious Disc to your Porygon2 to hold.
Then simply trade it to another player.
Porygon2 will evolve into Porygon-Z in the other player’s game, at which point you can trade back. Be aware that this evolution consumes the Dubious Disc permanently.
Is Porygon-Z Worth Using?
The Up-Grade allows the pitifully weak Porygon to evolve into the well-balanced fighter we know as Porygon2.
And the Dubious Disc will turn Porygon2 into a specialized sweeper, with a Special Attack stat even higher than that of Alakazam.
This comes at the cost of several of its other stats, though. Specifically Defense and Special Defense: Porygon-Z is much more breakable than its previous evolution.
Therefore, any strategies you might have employed with Porygon2 will likely need to be retooled for Porygon-Z.
Porygon-Z has one of two Abilities: Download and Adaptability.
Both are useful.
But Adaptability—which is brand new to Generation IV—is arguably the better ability. It boosts STAB damage inflicted by Porygon-Z by 2x instead of the standard 1.5x.
Pair Adaptability with a Normal-type special move like Tri-Attack, and suddenly you’re terrorizing your foes with a move that has a base power of 160 and perfect accuracy.
You can also set up your Porygon-Z as a “last resort” Pokémon by teaching it Hyper Beam, which will have an insane base power of 300 – all on a Pokémon with one of the highest Special Attack stats in the game.
The downside is Porygon-Z’s Normal typing, which won’t inflict super-effective damage to any type.
But considering how powerful Porygon-Z is, you might not notice a difference.