Is it even possible to do this in 2025? Thinking about running some old published adventure modules, but I have a couple of players whom I suspect will run to the internet and peek at things only the GM should know. Other than re-writing the adventure myself, can I even guard against this?
Just talk to them over the table about this spoiling the enjoyment. I had a version of this problem in my TOR table, where one of my players was playing an elf so he was looking up Tolkien lore through chatgpt so his character was appropriately knowledgeable, as an elf erudite should be. IMO this is awesome, but at one point I had to ask him to stop by clearly saying “hey, this stuff we are playing now is strictly from the RPG books, so looking it up will spoil some stuff” or “your character should know this and that about who these guys are”. Works out great