SnorlaxMonster
commented
3 years ago As an additional note, in both Diamond and Platinum, I found that one of the possible rooms between Pillar 2 and 3—the second one in Bulbapedia's collage—never has any wild encounters. You can verify this by using Sweet Scent or Honey. After noticing this, I checked every single possible Turnback Cave room in both Diamond and Platinum, and that room is the only inter-pillar room with that property.
magical
In the encounter data (and location area table), Turnback Cave has 7 areas within it: pillar-1 pillar-2 pillar-3 before-pillar-1 between-pillars-1-and-2 between-pillars-2-and-3 after-pillar-3
However, there are no wild encounters in the pillar rooms (or in Giratina's room, the only room after Pillar 3). You can easily verify this in-game by using Sweet Scent or Honey (after using Defog, as the fog will cause Sweet Scent/Honey to fail).
My first thought would be that these are just unused tables, but when I went and investigated the actual game data (via pokediamond disassembly and pokeplatinum disassembly), there are way more than simply 7 Turnback cave tables.
It appears that encountdata files 60 through to 105 all contain encounter data for Turnback Cave. From my reading of the data and in-game verification: -Files 60 to 62 are unused -Files 63 to 68 are for the 6 rooms that can appear between the entrance and Pillar 1 -Files 69 to 74 are for the 6 rooms that can appear between Pillar 1 and Pillar 2 -Files 75 to 80 are for the 6 rooms that can appear between Pillar 2 and Pillar 3* -Files 81 to 105 are unused
In Diamond and Pearl, the unused data is all just duplicated data of the Pillar 1-2 encounters. In Platinum, file 60 is a duplicate of Pillar 0-1; file 61 is a duplicate of Pillar 2-3; file 62 is unique (it's basically the same as Pillar 2-3, but a few Pokémon are Level 67 instead of 68); and files 81 through 105 are a set of encounters 10 levels higher than any the player can encounter.