Thanks to everyone who voted.
Yes, and they can use their knowledge in play: 19 (48%)
Yes, but they can't use their knowledge in play: 11 (28%)
No: 5 (12%)
Other: 4 (10%)
Total Votes: 39
Yes: totals out to 30 votes out of 39 for yes, which a majority allowing the knowledge to have value in play. Some comments on my previous post explained how that knowledge matters or doesn't matter, but I'd love to hear more. I already expounded on my approach but I would enjoy hearing others.
Only 12% don't allow their players to read the books. Which leads to the question, how do you stop them?
Is there a way to stop people from gaining knowledge of the game system's bestiary? I wonder especially for people who run D&D and OSR clones? - stopping them would entail stopping them from playing online games, D&D-based video games, or even read the whole of the Labyrinth Lord rulebook? I'm very curious - so if you've got a way to do it, let me know in the comments! I may need it someday . . .