The major, must-have expansion is
Fractures of Time. There's general consensus among the community that this "completes" Anachrony, adding a tremendous amount of tactical depth and expanding paths to victory. You're welcome to check the BGG forums, but the primacy of this expansion seems to be community consensus. Personally, I agree, and would strongly vote for this.
Otherwise, there are the "micro" expansions (modules) that players generally add to their games after a few plays, and then never remove after they've been incorporated. Among these are the
Alternate Timeline Variant, the
Variable Anomalies Module, as well as the
Interlocking Buildings and the
Neutronide Buildings additions. All of these are minor mini-expansions, and all of them make the game just slightly more interesting (and, in my opinion, better). They are easy to learn, and easy recommendations as improvements to the BGA implementation of this game. They are not, however,
essential.
What
is essential is adding some kind of additional way to spend Breakthroughs in the game. The base game, naked of expansions, does not provide enough outlets for Breakthroughs, and thus leaves the Research main-board action anemic and largely useless. The game's designer has posted on BGG noting that Breakthroughs are meant to be used more in expansions, and that the recommended way to play the game is with one "large" expansion (and some number of "small" expansions). Fractures of Time accomplishes this (as do the other "large" expansions). But Fractures of Time is also pretty involved, and may be difficult to implement. The smallest expansion that still does an excellent job of making Breakthroughs more important (which is pretty vital) is
The Quantum Loops Module, which was made available as part of the Future Imperfect expansion pack. This module is simple to understand and has few moving parts, and should be much easier to implement.
So, as a long-time experienced player of Anachrony, my priority-list suggestion for
most important expansions to implement in multiplayer Anachrony is:
- 1) Fractures of Time (or, if that's unrealistic, then The Quantum Loops Module)
2) Variable Anomalies
3) Variable Timeline
4) The Quantum Loops Module (or, if that became #1, then Fractures of Time)
5) Interlocking Buildings + Neutronide Buildings
6) Pioneers of New Earth
7) Intrigues of the Council
8) Hypersync Future Actions
9) Guardians of the Council
10) The Doomsday Module
11) Sentry Post / Promo Superprojects
(Please note that this list represents my own views, and is not meant to upset anyone. You're welcome to your own views about which expansions are most important, and to your own views about which expansions are best! One core strength of Anachrony is how incredibly flexible and customizable it is!)