In 'House Rules,' the group continues a house tradition, though specific details of the tradition are not explicitly described in the available summaries. The episode centers around this ongoing tradition as a key plot element.

The main characters involved in 'House Rules' include Issa, Anton, Samir, and Paul Baker. Issa and Anton are depicted as looking for meaning after an unexpected loss, while Samir and Paul Baker start underage drinking during the episode.

Issa and Anton experience an unexpected loss that prompts them to look for meaning, indicating a significant emotional moment that influences their actions and interactions in the episode.

In 'House Rules,' Paul Baker is involved in underage drinking with Samir, which ties into his broader storyline about relationships and personal challenges. This episode continues to develop his character arc within the group dynamic.

The episode features the main cast including Malik Elassal, Lucy Freyer, Jack Innanen, and Amita Rao, but there is no specific mention of new characters or notable guest appearances introduced in 'House Rules' based on the available information.