In the nostalgic version of Journey, the source of skill books was very wide. Some came from player drops, some from monster drops, and some came from mission rewards. The following are some common sources of skill books: 1. Player drops: Skill books are usually dropped by powerful monsters such as bats, giants, and dragons. These monsters usually had higher levels and powerful skills, so the possibility of dropping skill books was higher. 2. Monster drops: Some specific monsters will also drop skill books such as Skeleton King, Skeleton General, Zombie King, etc. These monsters usually had high levels and powerful skills, so the possibility of dropping skill books was also very high. 3. Mission Reward: After completing some missions, the mission reward may also include a skill book. For example, after completing the " Mysterious Treasure " quest, he would receive an Advanced Fireball Skill Book. It should be noted that the source of skill books is very wide, so different skill books may come from different monsters or quest rewards.