NOTE: I am doing this because I do not know how to make a library!

This is a readymade 'switching character' function and command. You can use this to switch between characters.
NOTE:You go in an order. I will update this so it'll show a menu(I'm too lazy now.)

Function

if (player.character = "Character 1") {
        msg ("You are playing as the second character.")
        player.character = "Character 2"
        c1.scenery = false
        c2.scenery = true
        MoveObject (player, c2.parent)
      }
      else if (player.character = "Character 2") {
        msg ("You are playing as the third character.")
        player.character = "Character 3"
        c2.scenery = false
        c3.scenery = true
        MoveObject (player, c3.parent)
      }
      else if (player.character = "Character 3") {
        msg ("You are playing as the fourth character.")
        player.character = "Character 4"
        c3.scenery = false
        c4.scenery = true
        MoveObject (player, c4.parent)
      }
      else if (player.character = "Character 4") {
        msg ("You are playing as the fifth character.")
        player.character = "Character 5"
        c4.scenery = false
        c5.scenery = true
        MoveObject (player, c5.parent)
      }
      else if (player.character = "Character 5") {
        if (GetBoolean(c6, "locked")) {
          msg ("You are playing as the first character.")
          player.character = "Character 1"
          c5.scenery = false
          c1.scenery = true
          MoveObject (player, c1.parent)
        }
        else {
          msg ("You are playing as the sixth character.")
          player.character = "Character 6"
          c5.scenery = false
          c6.scenery = true
          MoveObject (player, c6.parent)
        }
      }
      else if (player.character = "Character 6") {
        msg ("You are playing as the first character.")
        player.character = "Character 1"
        c6.scenery = false
        c1.scenery = true
        MoveObject (player, c1.parent)
      }
    }
  </function>

Command

<command name="switch">
    <pattern>switch</pattern>
    <script>
      SwitchCharacter
    </script>
  </command>

NOTE:Change your changeable character's names to 'c1' 'c2' etc. or it will not work! You can make what the player sees as the alias. If you have less than six characters then remove the needful. If you have more than six characters then learn from the code!

If you want you can copy your game's code and paste it into this file and continue creation after doing the desirable changes. You also can give me credit(Optional):

That's an interesting little script there, but I'm wondering if there's something missing?

At the moment, all it seems to do is modify the boolean value of c(x).scenery (not sure what this does?) and then move the player to the same room as another character object. I'm not sure how this is making you switch to another character though.

Hey sgreig, why don't you try that? It just 'fakes' the switching. If you type switch, c1 will be visible and c2 will not be. So to the player it will appear as if it changed.
You can also check if the player is a certain character. Just see if player.character = "Character X" where X is the number of your character.
You can also change the attiribute player.character to an integer.(number). I made it string for status attirbute properties.
Have fun with my code-cum-library!