Rollover is when most things happen. It's the process that takes place between turns when all your non-instant orders finally get carried out. Here is the order in which they happen:
- Artifacts are equipped.
- Units with attack and raid orders leave their starting territories.
- Units with move orders move to their new territories and join the defending army.
- Spells, operative abilities and building abilities (including upgrades) are cast.
- Buildings are built. However, defensive structures built now won't affect combat this turn.
- Resources are gathered.
- Raiding units hit their targets, briefly fight the defending armies there, and then begin to retreat.
- Attacking armies from territory A to territory B intercept and fight attacking armies from territory B to territory A. The winner's remaining forces continue the attack. The loser's remaining forces begin to retreat.
- Attacking armies hit their targets and fight the defending armies there. The winner's remaining forces stay in the attacked territory. The loser's remaining forces begin to retreat.
- New units are recruited. If the territory has been lost, new units begin to retreat.
- Provinces that have been captured change hands. Buildings in captured provinces are destroyed.
- Retreating armies attempt to go to the territory they were meant to finish in.
- Retreating armies whose intended territories are no longer under their control move to available adjacent territories or are killed if there are none.