Citadels; with the Dark City expansion; was the very first game that I played in my introduction to the newer board and card games. It is still one of my favourites.

Mechanics & Game Play:
The basic rules of the Citadels game remain unchanged. Instead at the beginning of the game a number of new Purple buildings may be added. Personally, I add five random buildings and remove the University (as I see no sense in it being the only 'duplicate' Purple building) This allows the new Purple cards to change on a game-to-game basis.

In addition, any number of the basic characters can be substituted for their Dark City counterparts. The rules say that only one or two should be swapped in. However the group I play with has had enormous fun using the whole lot. The new characters and their ability(s) are as follows.

1) The Witch: The Witch replaces The Assassin and has a similar effect. The witch's player names a character (in this case it is done after the player has taken their action). After the named character has taken their action, their turn ends, and the Witch may play the remainder of the turn as if they controlled that character.

2) The Tax Collector: The Tax Collector replaces The Thief and has the benefit that any player who builds one or more districts during their turn must give the Tax Collector 1 gold if they have one remaining at the end of the turn.

3) The Wizard: The Wizard replaces the Magician. The Wizard is allowed to look at another players hand and choose a district card. They may then choose to either add it to their hand or build it immediately in addition to their normal building that turn.

4) The Emperor: The Emperor replaces The King. When the Emperor is revealed the player moves the crown to another person (not themself). The recipient of the crown must give The Emperor either one gold or one card (givers choice). in addition, The Emperor receives one gold for each Yellow building.

5) The Abbot: The Abbot Replaces The Bishop. The Abbot forces the player with the most gold to give them one gold. In addition The Abbot receives one gold for each Blue building.

6) The Alchemist: The Alchemist replaces The Merchant. The Alchemist is allowed to retrieve all of the gold used to build buildings this turn (But may never spend more than they currently have). Unlike The Merchant, The Alchemist does NOT get gold for Green buildings.

7) The Navigator: The Navigator replaces The Architect. After the Navigator takes an action they receive either four gold or four cards, however they may not build any district cards.

8) The Diplomat: The Diplomat replaces The Warlord. The Diplomat is able to 'trade' districts in play with another player, paying the difference (if their building is less expensive, no gold is 'earned'). In addition, The Diplomat receives one gold for each Red building.

In addition to the replacements for the eight old characters, there are also two new characters.

9) The Queen: The Queen receives three gold if they were sitting next to The King (or Emperor) even if they were murdered.

9) The Artist: Te Artist can be used instead of The Queen. The artist is allowed to beautify up to two buildings by placing a gold on them. For all intents and purposes these buildings are treated as though they costed one additional point (i.e. they score one more point and they cost one more gold to destroy or trade).

Strategy:
The basic strategy remains unchanged. However the new characters often have different uses than their original counterparts. Still, the strategy remains to attempt to keep yourself hidden so that fewer people can target you, while you build your city. Some of the new Purple buildings also change the strategy slightly.

Components:
The components are the same quality as those in the basic game. The cards are made from moderate card stock and stand up to the rigors of gaming quite well, though I still sleeve them out of habit.

Number Of players:
The game is able to cater for between two and eight players. However two and three player games give the players more than one character card each and changes the dynamic of the game slightly. Probably at its best with five or six.

Play Time:
The game can be played in one hour, however the new characters can at times slow the game down and make it take longer.

Overall:
Overall I think that the Dark City Expansion is good enough that Citadels should not be played without it to a greater or lesser extent. Our group likes to add some of the expansion characters to the mix to alter the dynamic slightly and will more-often-than-not use The Emperor instead of The King. This expansion certainly has the ability to stop the game from getting old and stale.

For my review of the Citadels basic game please go to:
http://boardgamegeek.com/article/1600445