While the default backgrounds contained in the Pathfinder 2nd Edition can cover many things in the world of Eberron, sometimes you want something a bit more specific. See pg 60 of PF2 Core for more on Backgrounds.
Dragonmarked Houses
These are all Uncommon Backgrounds and should check with your GM before taking them. Information about Dragonmarked Houses can be found starting on pg 231 of the ECS 3.5. House backgrounds are to represent those that have grown up in the business of the House be it direct family, cousins or someone who has an apprenticeship within so there shouldn’t be any limits based on ancestry. All the following will have Lore in their appropriate House. While they of course can Recall Knowledge about their own House they should also be able to Recall Knowledge about other Houses but at an increased DC.
I also suggest, at GM’s Approval of course, to allow Dragonmarked Houses Lore to cover areas normally part of other skills IF appropriate for the House of course BUT once more at an increased DC or for more advanced things. Examples could be House Jorasco Lore to Administer First Aid or Treat Disease while House Vadalis Lore could Handle Animal on a horse or magebred animal.
Of course these backgrounds shouldn’t be required for a player to be part of a Dragonhouse as their plenty of fitting backgrounds; these are just expanded options to hand more flavor be it mechanical or just fluff.
House Cannith Background
Choose two ability boosts. One must be to Intelligence or Strength, and one is a free ability boost.
You’re trained in the Crafting skill and Dragonmarked House Cannith Lore skill. You gain the Quick Repair skill feat.
House Deneith Background
Choose two ability boosts. One must be to Strength or Charisma, and one is a free ability boost.
You’re trained in the Intimidation skill and Dragonmarked House Deneith Lore skill. You gain the Intimidating Glare skill feat.
House Ghallanda Background
Choose two ability boosts. One must be to Constitution or Charisma, and one is a free ability boost.
You’re trained in the Diplomacy skill and Dragonmarked House Ghallanda Lore skill. You gain either the Group Impression skill feat or Additional Lore skill feat for a type of food or drink.
House Jorasco Background
Choose two ability boosts. One must be to Wisdom or Constitution, and one is a free ability boost.
You’re trained in the Medicine skill and Dragonmarked House Jorasco Lore Skill. You gain the Assurance (Medicine) skill feat.
House Kundarak Background
Choose two ability boosts. One must be to Strength or Intelligence, and one is a free ability boost.
You’re trained in Society or Intimidate skill and in the Dragonmarked House Kundarak Lore skill. You gain the Experienced Professional Skill feat in Dragonmarked House Kundarak Lore or Intimidating Glare skill feat.
House Lyrandar Background
Choose two ability boosts. One must be Wisdom or Intelligence, and one is a free ability boost.
You’re trained in Nature or Survival skill and the Dragonmarked House Lyrandar Lore Skill.You gain the Additional Lore skill feat in either Sailor or Farming.
House Medani Background
Choose two Ability Boosts. One must be Wisdom or Dexterity, and one is a free ability boost.
You’re trained in Stealth or Society and the Dragonmarked House Medani Lore Skill. You gain Streetwise skill feat or Terrain Stalker.
House Orien Background
Choose two Ability Boosts. One must be Dexterity or Constitution and one is a free ability boost.
You’re trained in Stealth or Survival skill and the Drangonmarked House Orien Lore skill. You gain the Experienced Smuggler or Terrain Expertise skill feats.
House Phiarlan/Thurranni Background
Choose two Ability Boosts. One must be Charisma or Dexterity, and one is a free ability boost.
You’re trained in Performance skill and either the Drangonmarked House Phiarlan or Drangonmarked House Thurranni Lore skill. You gain the Fascinating Performance skill feat.
House Sivis Background
Choose two Ability Boosts. One must be Charisma or Intelligence, and one is a free ability boost.
You’re trained the Society or Diplomacy skill and the Drangonmarked House Sivis Lore skill.You gain the Multilingual or Group Impression skill feat.
House Tharashk Background
Choose two Ability Boosts. One must be Wisdom or Intelligence , and one is a free ability boost.
You’re trained in the Survival skill and the Drangonmarked House Thatashk Lore skill. You gain the Experienced Tracker skill feat.
House Vadalis Background
Choose two Ability Boosts. One must be Wisdom or Constitution, and one is a free ability boost.
You’re trained in the Nature skill and the Drangonmarked House Vadalis Lore skill You gain the Train Animal skill feat.