With these four new cards, going early in each round becomes a viable option. From now on, after passing, you send your scouts to explore the surrounding area to bring back a bonus: map, resource, ...
At the beginning of the game, place the four cards next to the players: this is the expedition reserve.
Once a player passes during the Action Phase, he can take an Expedition card of his choice and use it according to the rules on it.
The last player to pass does not take any cards.
Used Expedition cards are immediately returned to the Expedition Pool.