Space Empires: Replicators, the second expansion in the Space Empires series, adds a number of features to the base game, starting with the Replicators. Von-Neumann Machines ("Replicators") are self-replicating machines that behave, research, and reproduce differently from other empires, while having their own Empire Advantages. Replicators can be used by a fifth player, as an opponent in co-op games, or as a teaching empire for new players as the Replicator player doesn't have to fill out a production sheet or track the technology on his ships.

Space Empires: Replicators also includes hex-sized terrain tiles for planets, asteroids, nebulae, and other permanent terrain effects. When an exploration marker reveals a terrain effect that stays on the map, the exploration marker is removed and replaced by a tile, giving the map a nice visual effect. (By removing the exploration marker, this also creates more room in the hexes because now the entire hex is the terrain.) For epic games, the backs of some of these tiles can be used to connect two Space Empires Boards.

New Deep Space terrain is included in this expansion, with the Galactic Capital (which comes with its own scenario), Regional Map, Gravitational Anomaly, Space Pirates, and the Fold in Space.

Each player also is dealt his own (random) resource deck at the start of the game. Everyone starts with a hand of three cards and draws a new one each turn. These cards can be used as an event or turned in for CP. Cards impact battles, exploration, economics — almost every aspect of the game; they can add unpredictable twists and impact your strategy. More powerful resource cards require you to discard an extra card to play them.

New Ships are included in Space Empires: Replicators, with these ships requiring a new technology — Advanced Construction — to be researched. There are three levels of Advanced Construction, and it cannot be researched until the Economic Phase after your empire has built a BC or larger ship. Thus, they won't be available until the middle game at the earliest. The ships opened up by Advanced Construction include:

Battle Carriers (BV), which are large carriers that can fight well, carry six Fighters, and come equipped with Anti-Sensor Hull (immune to Mines). Fighter 4s can also be researched and built.
Advanced Destroyers (DDX) that can mount Attack 2, Defense 2, and come with Heavy Warheads (automatically hit on a 1 or a 2).
Advanced Raiders (RX) that can mount Attack 3, Defense 3, and can carry one ground unit!
All of the advanced ships can also be equipped with Fast technology (similar to BCs) if Fast 2 is researched. These changes don't impact the early and midgame, but make the DDs and Rs relevant in the late game. Raiders and Fighters are often curve balls that, once the opponent has reacted to them, lose their potency. This giv