I'm pretty new to editing ROMs. I'm playing Pokemon SoulSilver at the moment and wanted to make a few edits. Namely changing the Trade and Trade (Item) Evolutions to Level and Holding an item during day/night respectively, as well as adding unavailable Pokemon to some areas in the map.
Now I have two questions. I'm using PPRE 0.1.4 since PPRE 2 doesn't export ROM files for me and can't edit the map.
Firstly, after I changed all of the Evolutions (which was a bit cumbersome, since I had to save the Pokemon, switch to another and the back to the one I edited to be able to set the parameter for the new evolution type), I wrote a ROM and noticed that it was like 7 MB smaller than the original. I tried again setting the original ROM and created a new one without changing anything and the same happened again. I've read in another thread here that the file gets smaller because a lot of junk code is deleted. I just wanted to make sure if this is correct and if it has any effect on the game whatsoever.
My second question is about the map editing in general. When I open Route 29 for example, I see a list of 12 Pokemon for each time of the day and the corresponding levels. How are the probabilities to encounter a Pokemon calculated? Especially the 1% ones like Dunsparce in Dark Cave. When I look at Route 32 for example, I see Tentacruel thrice in the Surf section and both Tentacool and Quagsire once. However, they seem to have much higher probabilities to be encountered than Tentacruel. It confuses me a bit.
Also, how is the level of Hoenn/Sinnoh Noise Pokemon determined and where do I find the Headbutt Pokemon in each area? Or were these just not implemented?
I do understand that PPRE doesn't seem to be developed anymore and many have moved to newer generations, but I hope that someone can still help me.
At least for land Pokemon, I think I can see a pattern of 4x15%, 2x10%, 2x5%, 3%, 4%, 2% and 1% from top to bottom and the Pokemon being arranged accordingly.
Okay, I think I got the probabilities, wasn't as hard as I imagined. Surf has 60%, 30%, 5% and I guess like 3% and 2% or so, while the Rods have 35%, 30%, 20%, 10% and 5%, all from top to bottom. Not sure about that though.