How to split your game across multiple RPG files
Are a thousand tags just not enough for your dream game? Do you want to have 200 maps so that you can have tilesets with more detail, with each map being only a couple of rooms? Well, all this is quite possible through the magic of splitting your game across multiple RPG files. For the confused, splitting your game across RPG files means that you'd have some of your game on one RPG file, then more (or the rest) on another RPG file. This essentially lets you extend some of your game's limits (maps, tags (although I'd think 1000 is plenty more than enough), etc.). How is such a thing done? Well, that's what I'm here for.
Note that for the duration of this tutorial, I'm going to assume you want to split your RPG file for the sake of more maps, since that's probably what most people will want. If you use something else like tags, the same principles basically apply (transition maps, using a few identical tags, etc.)
The first step to splitting your game is to first make the first RPG file. Make EVERYTHING in this RPG file regarding monsters, attacks, heroes, etc. Monsters that go in the second half of the game should still be placed in the first RPG file (it just makes things easier). Textboxes in the second half go in the first RPG file. Tilesets, graphics, all that stuff. Make everything you can. Once you've filled up 99 of your 100 maps, make a final map. This map is special. For the sake of this tutorial, I'm going to call this the transition map. At some point in your game, when you want the first half (or first part) to end, end it, then move your heroes to the transition map (you may want to have all your blank black tiles on this map be 'overhead' to hide your heroes). Call a save shop, and make sure you let the player know that you MUST save here in order to be able to continue in the game. After that, set a tag on that is named something like "End of Part 1" and end the game.
Now, for the mechanics of your second RPG file. Make a copy of your first RPG file and rename it, then load it in CUSTOM. Delete all your maps except the transition map (double-check that the transition map in RPG file 1 and the transition map in RPG file 2 have the same number, name, everything. They must be identical). Now make your second RPG file and use the other 99 maps you have available. Once you've filled up everything and are done, write a script to be set upon loading a saved game. It won't be difficult to do at all, just write a script that checks to see if the hero is on the transition map, and if "End of Part 1" is on. If so, teleport the hero to a new map (the map you should start Part 2 on). Then set "End of Part 1" off.
If you want the player to be able to return to the first part for some reason, you'd do something similar. Make a place where you want the hero to go to the transition map, then move them there, call a save shop, and set a tag on that says "Return to Part 1". On the first file, set a load-game script that checks if the player is on the transition map and if "Return to Part 1" is on. If so, teleport them to a new map (remember, both RPG files must share the same tags, and that the transition maps must be identical EXCEPT for their scripts).
Now, how does the save file get converted? "Quite easily", says I. The best and easiest thing you can do for the player is to write a batch file. The batch file will convert the saves from the first game into saves from the second game. Be warned that there isn't an easy way to check to make sure the player doesn't load a save not in a transition room (and I'm not the person to ask questions on regarding that, because I'm not a programmer), so warn the player that if they load another save that they may encounter problems (you can probably add a bit to your load-game script that if they aren't on the transition map then they move to it (assuming End Part 1/Return Part 1 is ON)). The batch file is very easy to make. Right click anywhere in the folder and make a new text document, then rename it to what you want the conversion program to be called (can't be more than eight letters). After that, open it and type in the following few lines:
echo Save File Converter
echo *Searching for save file...
echo *Making backup of save file...
copy mygame.sav mygame.bak >nul
echo *Creating Part 2 save file...
copy mygame.sav mygamep2.sav
echo *New Save File created.
echo You can now run part two.
echo Your save file backup is 'mygame.bak'.
Of course, with that you can see what it does, then go back and edit it and pretty it up a bit if you want (change the wording of what appears, etc.). To run this, rename it so that the extention is .bat, then double-click it. It will make a copy of your .sav file, back it up, then rename the
copy to that of the other RPG file.