At the end of any turn, any nation may offer to conditionally surrender to any number of enemy nations. The surrender does not have to be accepted, but if any nation declines, it may influence the entry of a Neutral Major Power (see Phase 13: Special Game Options). The nation that offered the surrender remains at war with any nations that do not accept the surrender.
The terms of surrender are as follows: The surrendering nation and all nations that accept the surrender are no longer at war. If the surrendering nation has control of territories originally held by the nation(s) accepting the surrender, all of those territories revert back to their original owners control. Any units owned by the surrendering nation within those territories are moved to the nearest territory still under the surrendering nation's control.
Any territories held and incorporated by the nation(s) accepting the surrender (victorious nations) remain under those nations control. The victorious nation(s) cannot declare war on the surrendering nation on any future turn. The surrendering nation must give 1/4 of its remaining resources it collects every turn to the victorious nation(s). This giving of resources (war tribute) continues until such a time that the surrendering nation is again at war with the victorious nation(s) or two full years have passed (12 turns) since the surrender. The surrendering nation may declare war upon the victors again any time after three turns have passed since the surrender, but doing so may affect the entry of Neutral Major powers. A nation may surrender only once per game. If they have surrendered, then re-enter the war, they may not offer to surrender again. They may, however, still accept surrenders offered to them.