Personality defines how the AI plays that race. In certain situations, the AI will follow specific strategies based on its personality. Personality also affects diplomatic disposition, as well as voting behavior in the United Planets. Some traits also add flavor text when the player is using that race, or when the AI is speaking to the player.
When playing as a custom race, the player can specify its personality. It is best to keep the personality traits to around three, or the race will have conflicting interests, and will play generically.
More information on Personality traits can be found on the list below.
| Trait | Description | Flavor Text |
|---|---|---|
| Benevolent | Favors benevolent ideological choices. | |
| Neutral | Favors pragmatic ideological choices. | |
| Merciless | Favors malevolent ideological choices. | |
| Aggressive | More likely to take extreme action in response to diplomatic slights. They start considering war sooner, highly value war and embargo treaties against their enemies and are infuriated by refusing tribute and other requests. They could not care less if the player is dubbed a War Monger, but are furious if the player is friends or allies with an enemy. | If the player is an easy target, they speak openly about conquering their planets. |
| Peaceful | More likely to select a moderate response to diplomatic slights, and emphasizes things in common to promote harmony. Effects of Diplomatic minuses are halved, Diplomatic pluses are doubled, considers war only as a last resort, preferring embargoes instead. They do not take kindly to breaking treaties, having a strong military, and picking on a War Victim or a nice civilization. More favorable to civilization with a high  Diplomacy Bonus. |
|
| Cruel | Tendency to pick on weaker players, and cares less about cultural animosity (no minus or plus from Ideology, extreme minuses from being weak and ripe for conquest, no minus for strong military). | May fantasize about eating the other leaders, flaying them alive, or making them their servants. |
| Expansionist | Prioritizes opportunities to expand their empire. (If they see a planet, they will immediately attempt to colonize it, highly values colonization tech). | |
| Greedy | Prioritizes opportunity to increase their treasury by any means. (Values trade routes and money trades more than usual) | |
| Opportunistic | Values chance to come out ahead in any situation. (They demand more when trading). | |
| Scientific | Prioritizes technology research and trade. (Values research and techs very highly in trades) | May look forward to studying or sharing knowledge with the other leaders. |
| Diplomatic | Prioritizes effectiveness in diplomatic communication. (Will often try to make beneficial treaties with others) | Acts friendly towards the other leaders, and talks of working together. |
| Cultural | Values things that increase their influence in the galaxy. (They value influence very highly and are easily offended by brazen attempts at cultural takeover) | |
| Spiritual | Places increased importance on ideological choices. (Ideology diplomatic bonus/penalty is doubled). | Regards their enemies as blasphemers and sinners. |
| Trader | Seeks opportunities for peaceful trade. (double diplomatic bonus from trade routes, will make freighters at first opportunity) | Looks forward to trading with the other leaders. |
| Xenophobic | More distrustful of all factions. (All diplomatic bonuses are halved, and all diplomatic penalties are doubled) | Appears disgusted at the sight of the other leaders, loves the phrase "go away". |