version 1/120327 by Kevin Norris
Possessing is an action out of world applying to a visible person. By default, any playable characters are placed in scope, in addition to whatever the player can see. Playability is determined by a flag:
Alice is playable.
Bob is not playable. [the default]
At the time when the situation worsens:
Say "Bob looks concerned for a moment. 'Let me help you,' he says.";
Now Bob is playable.
At the time when Alice is captured:
Now Alice is not playable.
If the player tries to possess an NPC, the game will respond with a list of playable characters. If no characters are playable, the game will report this. Otherwise, the game will set the named person as the player. If the new player is not in the same location as the old player, a look action will also be generated.
Note that in the last example, if Alice was the player, she will still be the player after the flag is turned off. You must manually change the player if this happens. Although there won't be any serious problems from having a non-playable player, in most practical circumstances you will want to avoid this situation.
Keep in mind that, by default, the player is not playable; if you want to allow the player to get back to their body after possessing someone else, you'll need to mark them as playable.
By default, persuasion succeeds for any playable character. The block giving rule has also been modified to allow the player and NPCs to give things to playable characters, and to make the player accept any gifts offered. See the giving it to action under the index if you want to change this.