Sequels and expansions have long been an accepted part of video game culture. Since the popularity of Pac-Man spawned its sequels, most major video game franchises have been blessed (or cursed) with sequels.
For tabletop games, the tendency to create sequels and expansions has been much less, but with the more recent wave of board game popularity, board game sequels and expansions are increasing in frequency. In fact, we are getting to the point where more board games have sequels than not, and we can recognize that there are many great games that need sequels but haven't gotten them, and likely won't.
10 Pandemic Legacy Season 2
Let's get this out there: supposedly, Pandemic Legacy Season 3 is coming. There have been hints in various places that the design is in various stages, but there are also reasons to fear that it might never see the light of day. The last sort of official announcement about Season 3 was more than a year ago. The announcement said that the game was supposed to be released in October or November 2019. As last as August, an interview with co-designer Rob Daviau stated that the game design for Pandemic Legacy Season 3 was done and that it was with the publisher.
But there's no official news about it on the Z-Man Games site. There are many reasons why the game might never see the light of day. The publisher might not like the design. The economics of legacy games has changed. Season 2 didn't sell well enough or wasn't received well enough. Maybe there's not enough buzz around a Season 3. This is one where we'd love to be proven wrong but are pessimistic that we're right.
9 Colossal Arena
In Colossal Arena, you play as gamblers on gladiatorial combat between the monsters of myth and legend. Ten monsters enter the arena, but after five round of combat, only five will survive. If you have the most bets on those five monsters, you win.
The strategy in this game is tense, and the monsters' special powers add interesting wrinkles to the game. An expansion could give additional monsters, with new abilities to further enrich the play of this game. But, more than 12 years after Fantasy Flight reissued this game, it seems unlikely that we'll get the expansion.
8 Risk: 2210
We know, there are enough Risk games out there to choke a herd of baby elephants. Why should we look for one more expansion or variation? Risk: 2210 was an attempt to update the classic strategy game with new mechanics that added play depth to make it more like the advanced strategy games that were coming out at the time. And it worked.
With additional complexities, including the addition of 8-sided dice and strategic cards, the game felt much more nuanced and interesting. While there have been numerous fan-made additions, the main game hasn't gotten an expansion (though in some ways Risk: Legacy is a spiritual sequel).
7 Histrio
Histrio is a fun game where you attempt to recruit performers for your theater troupe, then put on a show for the king. If your show matches the mood of the king, you get paid, and even more, if your show is the most pleasing.
The dynamic of the game allows for lots of player interaction, and the fun artwork of courtly animals makes the game enjoyable. Plus, it has a good physicality in its textured coins and the three-dimensional stage. An expansion could give additional performers, new secret missions, and maybe even an additional player, but, alas, we are unlikely to see it.
6 Kaiju, Inc.
Kaiju, Incorporated is a fun little game inspired by Pacific Rim. Players compete to make the most profit from kaiju, making derivative products from kaiju burgers to mutating hair cream to kaiju skin handbags.
The game has some fun player interactions, and the cards are all clever, full of Easter eggs for fans of Godzilla, Gamera, and their ilk. If it has one weakness, it's that the jokes become less interesting with repeated plays, so an expansion that added new jokes, as well as new interactions, could breathe new life into the game. But, unfortunately, that's not going to happen.
5 Red November
In this frenetic coop game, you play as gnome sailors on the fleet's new flagship submarine, the Red November. With an innovative mechanism for tracking "simultaneous" action, this game plays like virtually nothing else out there.
Between fire, flooding, malfunctions, and crew members passing out from grog, it's very hard to survive the maiden voyage even before the Kraken shows up. This game deserves a sequel that puts the Red November into a different situation and adds new types of mayhem. But it seems the ship has sailed on that option.
4 Dungeon!
This dungeon crawler was really ahead of its time. It tried to simplify Dungeons & Dragons down to a simpler game of moving through rooms, killing monsters, and collecting treasure.
By and large, it works. But its main limitation is that there are only so many monsters and treasures in the dungeon. This limits replayability. But the game could get a completely new life with an alternate set of cards. This would do more for improving the reception of the game than reissuing it with new box art every few years.
3 Cleopatra and the Society of Architects
In this game, players compete to gather the resources necessary to build an Egyptian temple, including sphinxes, obelisks, and decorated walls. The game has well-made plastic components for the temple, making it feel like you're really building something.
One aspect of the game that makes it interesting is corruption. People gain corruption when they use certain higher-value resources, and they put this corruption inside a small pyramid so that no one knows how much corruption each person has. At the end of the game, the one with the most corruption gets fed to the crocodiles. A sequel could come with different temple pieces for this underappreciated game.
2 Gaia
Not to be confused with The Gaia Project, this game was made by the Tiki Brand (yeah, the people famous for the yard torches). It's an interesting little game where you build a world and try to populate it with your people. Divine powers allow you to transform the world once built using creative disasters. This is a fun and interesting game that is light on rules but with some surprising strategic angles. And it plays in under an hour.
An expansion could add more terrain types, different divine powers, and maybe roll in the tiny, limited issue expansion.
1 Twilight Imperium
Twilight Imperium is really the quintessential galactic 4X game. Incorporating epic space battles, interesting political maneuvering, and technological advancement, this game has it all. Even better, the fourth edition streamlined the rules, making the gameplay in half the time without losing the flavor.
Unfortunately, there are no expansions for the fourth edition, even though each of the previous editions had multiple ones. We know this isn't likely to see an expansion because the base set included all 17 races from the third edition and the creator retired shortly after the fourth edition's release.