Game ID: ReticulanRebels This event happens after human territory borders the Reticulan. Due to the proximity of the two sides, this is always caused by either side occupying one of the three territories to the South of Home Base.
This event mentions an alliance proposal from the Reticulan. This is always the first diplomacy deal in the game, but accepting it is not mandatory. Until the proposal is accepted, the Reticulans will invade Humans land as usual.
The Reticulans will keep offering alliance, even if the Humans keep attacking them, at least under normal difficulty. This can be used to accumulate loots and captives, and to gain access to the Reticulan main base, before forming an alliance (usually temporary).