Optional effects are powers that the player may invoke, such as the Pawnshop's ability to convert dice or the Wizard's Keep's extra turn. Mandatory effects begin immediately upon playing the card. Optional effects cannot be used the turn the card is played, but can be used during the next player's turn. A variant with two or more decks will be interesting, I think. With the expansion set, adding this rule is a good idea.
Players replace starting with the phasing player and continuing clockwise.
This may make some events' durations very short. The new resource must be spent this turn. Even with these changes, the Pawnshop is one of the most powerful cards in the game. Woe to the player on the Pawnshop 's left. Two Residence s are worth only 3 VPs.