Theme Booster

Magic Theme Boosters were booster packs targeted at deckbuilding players, providing a number of cards from a certain expansion set that could go straight into their deck. They also played up a set's flavor for those that might be interested in sampling a slice of a particular aspect of the world.
Theme Boosters contained 35 cards (a variable amount of commons and uncommons, and 1 or 2 rares or mythic rares) from a given color or theme. The MSRP was $6.99. 
==History==
With the release of Dominaria, Wizards of the Coast began testing a new product at 300 Walmart locations across North America called the “Dominaria Theme Booster”. These contained 35 cards (a variable amount of commons and uncommons, and one rare or mythic rare) from a given color and theme, as well as artifacts and colorless cards. The MSRP is $6.99. By limiting this test to a single large account, WotC hoped to perform a controlled test that allowed them to more efficiently and accurately interpret sales results that would help inform future decisions about this kind of product.Dominaria Themed Boosters Found at Walmart (Reddit)
Apparently deemed a success, Theme Boosters also appeared with Guilds of Ravnica. This time around, they were bi-colored.Barry White (August 15, 2018). "Guild of Ravnica Theme Boosters, Guild Packs Detailed by WotC". GeekNifty.com Later, Wizards of the Coast announced that Theme Boosters would be part of each main set's lineup going forward. The composition of these theme boosters differs depending on the properties of the set.
Starting with Throne of Eldraine, nine out of ten Theme Boosters had one rare, but one out of ten had two rares. The number of commons and uncommons still varied between boosters, unlike Draft Boosters where the number of each rarity mostly remains constant. You always would get more commons than uncommons, however. A reference card was added to help expose newer players to different aspects of the game.
Theros Beyond Death featured 10 unique rares which could appear in the rare slot(s) of a theme booster. These did not appear in draft boosters, but had a chance of appearing in the ancillary slot of the set's collector boosters. Kaldheim had similar extra cards.
Core Set 2021 did not feature Theme Boosters.
Starting with Dominaria United in 2022, Jumpstart Boosters replaced Theme Boosters for Premier sets. 
In retrospect, Theme Boosters didn't perform all that well. They aren't expected to return.
==Sets with theme boosters==
Set 	1 	2 	3 	4 	5 	Extra 	Notes
Dominaria 	 	 	 	 	 	 	
Guilds of Ravnica 	(Selesnya) 	(Boros) 	(Golgari) 	(Izzet) 	(Dimir) 	 	
Ravnica Allegiance 	(Azorius) 	(Rakdos) 	(Gruul) 	(Simic) 	(Orzhov) 	 	
War of the Spark 	 	 	 	 	 	 	
Core Set 2020 	 	 	 	 	 	 	
Throne of Eldraine 	 	 	 	 	 	 	
Theros Beyond Death 	 	 	 	 	 	 	Each pack contains 2 out of a possible 10 rare cardsthat are not part of the main set.
Ikoria: Lair of Behemoths 	 	 	 	 	 	(Monsters) 	
Zendikar Rising 	 	 	 	 	 	(Party) 	
Kaldheim 	 	 	 	 	 	(Vikings) 	Each pack may contain several out of a possible 15 uncommon cardsthat are not part of the main set.
Strixhaven: School of Mages 	(Silverquill)	(Prismari)	(Witherbloom)	(Lorehold) 	(Quandrix)	 	
Adventures in the Forgotten Realms	 	 	 	 	 	(Dungeons) 	Arena advert cards are replaced with dungeon cards.
Innistrad: Midnight Hunt 	 	 	 	 	 	(Werewolves)	
Innistrad: Crimson Vow 	 	 	 	 	 	(Vampires) 	
Kamigawa: Neon Dynasty 	 	 	 	 	 	(Ninjas) 	
Streets of New Capenna 	(Obscura) 	(Maestros)	(Riveteers) 	(Cabaretti)	(Brokers) 	 	
==References==