A very simple system for having characters know more about the world around them. This will mesh perfectly with a setting that prioritizes harvesting parts from kills.

This supplement presents an interesting idea for determining whether or not a character knows something about a given monster type without introducing a slew of new mechanics to accomplish such. However, the mechanics are a bit inflexible and a little illogical at times; essentially, every class can add their proficiency bonus to Intelligence checks to know something relevant about a particular monster, but as the other reviewer below noted, each class is locked into knowing something about a particular type of monster. Rangers, for example, can add their bonus to checks about monstrosities, and Barbarians can for beasts. It seems a little odd, though, that a Ranger seems to have no particular knowledge about beasts or giants. In attempting to make each class have its own particular field of knowledge, monster lore ends up getting divided up in ways which seem forced and unlikely. I think it would be fine for some classes to be better than others at such and also for some overlap to occur.

This is something our group has struggled with now and then because this isn't really handled in any of the core books. I like the match ups between monster type and skill and I really like the table that describes how having a better success on the skill check gives more information. On the other hand, I think the class affinity seem a little forced. Almost as if they were trying to find something for every class to be good at. Our group is more likely to grant the affinity bonus more on whether the individual character can justify it... for example, a fey patron warlock has good reason to know more about fey.

All in all though, it's a far better approach to the issue than what is currently in the core books.