Endless Space Faction Design

Endless Space: Custom Factions (tuned for human multiplayer) (Work in progress)

First you need to decide what victory condition you will pursue: Supremacy/Expansion, or Science. Dust/Wonder are also possibilities for certain races, but the Ind-Sci conversion bug (http://pastebin.com/MAGkrVCg) advantages a Science victory.

Second, there are three basic types of factions you can design: rush military (ideal for smaller games), balanced factions, and growth factions. If you are going for Supremacy you are likely deciding between the former two, and if you are going for Science you are deciding between the latter two. Between identical skill players and no luck involved, rush beats growth beats balanced beats rush...in practice it never works out that simply.

Finally you can select your affinity.

Amoeba: The biggest strike against them is that the Diplomatic victory is virtually unachievable before another opponent wins a science victory. Their affinity allows you to beeline for the best systems, as well as immediately receive full trade bonuses upon meeting an opponent. Their affinity techs make their trade routes are best in class - unfortunately trade routes are not the most significant source of science and dust (especially with the Ind-Sci conversion bug) - and they receive approval bonuses from a variety of peace activities. Only go Amoeba if you are sure there are very few opposing factions taking the "Eternal War" trait, as you are completely useless to each other.

Automaton: A fiddly race with high capability, the Ind-Sci conversion bug severely limits their potential. "Short-Range Entanglement" grants them bonus FIDS minus their owned portion of the galaxy is fantastic in a large game if you are able to grab only premiere systems. A Wonder victory is possible for them.

Cravers: The Ind-Sci conversion bug shortens games, which blunts one of their biggest weaknesses (overexploitation). They have a smooth power curve, starting out as the strongest faction with their 25% overexploitation bonus FIDS, and hitting solid power spikes with two techs:

Harmony:
Hissho:
Horatio:
Pilgrims:
Sheredyn:
Sophons:
Sowers:
United Empire:
Vaulters: