From the Comprehensive Rules 4.0:
Each other player in the game, starting with the player immediately to your right, has one Shadow phase.
During each player’s Shadow phase, that player may perform Shadow actions in any order, including playing most Shadow cards.
Perform Shadow actions
One Shadow action is always available:
- Play a Shadow minion, possession, artifact, or condition from your hand to the table.
A Shadow player may find other Shadow actions on events in his hand, or as special abilities on cards he already has in play.
When one Shadow player has completed all of the Shadow actions he wishes to perform, the next Shadow player to his right (if any) then performs a Shadow phase.
All Shadow players pay for cards by using the same twilight pool. The second Shadow player uses twilight tokens left over from the first Shadow player, and so on.
You may use (and exert) another player’s character to pay a cost for your Shadow card or special ability.
Playing Shadow cards
A minion is played to the center of the table, across from the active fellowship. Artifacts, possessions, and conditions state in their game text where they play.
Each minion is normally played to a certain range of sites beginning with the minion’s site number. If the minion is played to (or is currently at) a site that has a lower site number, that minion is roaming. The player must pay a roaming penalty by removing an additional two twilight tokens when playing that minion.
A Shadow player cannot play a Shadow artifact, condition, or possession on another Shadow player’s minion, or to another player’s support area. However, Shadow cards may give bonuses or other game effects to other players’ Shadow cards, and Shadow players may play events for other players’ Shadow cards as appropriate.
When all Shadow players have each completed a Shadow phase, proceed to the maneuver phase. If there are no minions in play at the end of the final Shadow phase, then skip directly to the regroup phase.