Dungons & Dragons
Some others of interest on the site, but here are a few. They are limited time offers.
Dungeons & Dragons bundle from Kobold Press
https://www.humblebundle.com/books/heroic-hoard-5e-power-kobold-press-books?hmb_source=&hmb_medium=product_tile&hmb_campaign=mosaic_section_1_layout_index_2_layout_type_threes_tile_index_2_c_heroichoard5epowerkoboldpress_bookbundle
Goodman Games for Dungeons & Dragons and Dungeon Crawl Classics
https://www.humblebundle.com/books/megadungeon-megabundle-for-dcc-5e-goodman-games-books?hmb_source=&hmb_medium=product_tile&hmb_campaign=mosaic_section_1_layout_index_4_layout_type_threes_tile_index_1_c_megadungeonmegabundlefordcc5egoodmangames_bookbundle
Steamforged Games Iron Kingdoms Collection for the Iron Kingdoms Roleplaying Game and Iron Kingdoms 5e
https://www.humblebundle.com/books/iron-kingdoms-collection-steamforged-books?hmb_source=&hmb_medium=product_tile&hmb_campaign=mosaic_section_1_layout_index_3_layout_type_threes_tile_index_2_c_ironkingdomscollectionsteamforged_bookbundle
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