In minecraft, difficulty settings can be changed anytime, and this is in fact (normally) a great feature. Yet, for some reasons given below, I am looking for an option to disable this feature, may it be by a mod or whatever. Does anybody know a way to lock the difficulty setting once a game is created? Or even better (for my purposes): How can I enforce that new games will always use a predetermined, fixed difficulty that cannot be changed?
Some explanation: I have seen many discussions of such a question in the web being stalled by comments like "Aww, man, just show some willpower and don't switch the setting!" In the problem at hand, I am preparing a (single-player) installation of Minecraft for my niece and nephew. They love the game, but they are quite young, and being attacked by a bunch of scary spiders will most certainly lead to severe nightmares, that much I am sure. Hence, I want to technically prevent them from changing the difficulty (either on purpose or by accident) to something other than "peaceful". So please, consider this question as valid.