Is making bot-NPC, which will act like players allowed and can be helpfull?

Hello, guys. I’m making a game, where players can do a lot of diffirent things. But now, it’s hard to make game popular, because it need some social environment, like some other players which you can talk with if you bored. Otherwise, player will just leave. Also, some parts of my game requires help of other players.

So, I got an idea to make NPCs which will act like player, if there’s low player count on server. So you will be able to do with him everything you can with normal player. I know that this’s hard, and maybe impossible, but I got some questions about this idea:

  1. Is it even allowed to make this?
  2. Should I state somewhere, that you can meet bot, and not actual player, or I can keep this as secret?
  3. Should I cut possiblities of bots?
  1. I don’t see why It wouldn’t be allowed (Don’t take my word on it) but I’ve seen games fake players and make them send messages.
  2. I think you should state that it’s not an actual player, can already expect people talking to the bot and getting mad they don’t answer, but keeping it as a secret can be a good idea until they check the player list.
  3. It really depends on what game you’re making this on, a shooter? great idea, Some type of puzzle game? not so great.