PCs from regions strongly influenced by celestials (or studying such places) may roll the History Check on the Religion table. Some celestials might be strongly related to certain religions (as preferred emissaries for example), which might grant PCs of that religion advantage on their roll.

For constructs famous in a region a PC has studied intensively or comes from, they may roll the History check on the Arcana table. If the PC's religion is strongly related to the forge or artifact building, they may roll the Religion check on the History table. Artificers may have good reasons to know more about constructs, granting them advantage.

If Dragons have influenced a certain region a PC has studied or comes from, they could roll the History roll on the Arcana table. Dragonborns or Draconic Sorcerers might have some extra information concerning their dragon ancestor, granting them advantage to their roll.

If a specific studied region has special links with Elementals, the History check may be rolled on the Religion table. If the PC's religion is closely affiliated to a specific element, they might roll the Religion check on the Arcana table for informations on Elementals affiliated to that element. Genasi could have advantage on related elementals.

For PCs from regions with a strong presence of Fey, History checks can be rolled on the Arcana table. This might also be the case for religions with strong links to Feykind. Archfey Warlocks and Circle of Dreams Druids could also obtain advantage to their checks due to their proximity.

PCS from places having (usually negative) interactions with Fiends might roll History (or Nature for Rangers and Druids) checks on the Arcana table. Pact of the Fiend Warlocks or Horizon Walker Rangers may have advantage to their rolls due to their relations with those creatures.

For races with strong links to magic, the DM might authorise rolling Arcana checks on the Nature table. If a PC's religion is connected with a specific race, Religion checks on that race could also be rolled on the History table. PCs from specific races should have automatic access to advanced knowledge.

PC's whose religion has links with monstrous species may roll Religion checks on the History table if there are links between the specie and the creature researched. A PC coming from a place with heavy interaction with certain species might roll a History check on the Arcana/Nature table.

In regions close to dungeons, large underground caverns or magical labs, PCs with relevant knowledge may make History checks about Oozes on the Nature table. PCs having lived underground or in marshes could roll Nature checks on the Arcana table if oozes are a common threat in those environment. Someone crazy enough to venerate Juiblex might deserve advantage.

Plants used intensively in alchemy or as magical reagents may warrant a roll of Arcana on the History table. Specific plants having a special history with some places could also have PCs having studied them roll History checks on the Nature table. PCs whose religion has links to nature or flora specifically might roll Religion checks on the Nature table.

PC who have studied regions affected by undeads may roll a History check on the Arcana table. PCs whose religion is closely linked with Life and/or Death could roll Religion checks with advantage. An Undying Warlock or Long Death Monk may also have advantage in some cases.