Party Switching
Hey there RRR, I was working on a party switching system today and thought "Hey this was a bit tough to do. Some newbies might struggle with this. Maybe I should post a tutorial about this on RRR?" and here I am. I've created a small demo that shows the basic layout of the party switching system. Hope you enjoy it!
ProcedureMake your map. Then make a set of 3 new events. Place them in corner of the map where the player cannot see or reach them. Set the graphics of two of them to your two party leaders. Leave the rest of the event blank. Set the trigger of the other event to "Parallel Process". Now in the event command section, add in a Conditional Branch "The Button X is being pressed" and set handling conditions for when it does not apply.
Now here's where it gets tricky. Go into the control variables command and make 3 new variables which are equal to the player's: Map X, Map Y and the Map ID. Now, remove the first party leader, add in the second one, Set the Event Location of the event representing the first leader to the three variables you just created. Now, add in a teleport event for the second leader, preferably away from the first leader. Add in a Control Self Switch A = On command.
Make a new event page and copy over all the commands but rearrange it to look like this:
The first event page should look something like this:

And the second event page should look like this:

Download and try the demo to see this in action!
DemoMediafireCreditsEnterbrain for making RPG Maker VX
Kiyoto Kaduki for his character sprites used in this demo