The answer is both less -- and more -- than it seems.
The "less" is that there's literally nothing actually new as far as game mechanics go in this expansion. There are no new rules or abilities. The only point of departure, aside from naming the units after various historical forces, is a set of cards with Army-specific "Divine Rituals" that their associated clerics can invoke, much the same as the wizard spells in standard Wizard Kings.
It's also "less" in that there's nothing to prevent a player from mixing in the new units with his existing Wizard Kings armies or spicing up his Ancient Kings armies with Chaos creatures, were-beasts, artifacts, heroes or treasures from WK. In many ways WK is a game kit, more than just a game, and the exact nature of the game YOU play will depend not just on the scenarios selected, but the armies you own, the expansions you have bought, your choice of maps and even the specific units you build during the course of a game.
If you do mix, some of the combos might seem a bit unsettling. The block color
It can be "more" however, in my opinion, if you
One of the fascinating things about block games is how subtle changes can have a big impact in the way the game plays, despite relatively minor changes in game mechanics. Games such as Hammer of the Scots, Crusader Rex and Richard III: The Wars of the Roses share very similar game systems, but play quite uniquely.
Ancient Kings provides a much more military game than the more fantastic Wizard Kings. For one thing, the Chaos and Were-creatures do not figure in the game, unless of course you add some in from WK. This is not to say that the Ancient Kings armies are historical -- they are not. Aside from many anachronisms in the unit mix, there are also some fantasy elements in some of the armies. The Chinese have dragons, for example, and the Greeks have cyclops. And the there are the Gods, of course.
So Ancient Kings is clearly a history-themed game, not a historical wargame. This is not Julius Caesar.
The game will play out in a more military way because of the mix of unit capabilities that are present and what appears to be a deliberate attempt to accentuate the differences between the armies.
While every army has the same basic core units you'd expect -- such as cheap spearmen, some horse, forts and ships, there are also units unique to each and the mix provide by the semi-collectible nature of the expansion boxes mean that unless you spend a fortune, your armies are going to have different mixes of options when its time to build.
This is true of Wizard Kings as well, of course, although the Chaos units do a lot to blur those distinctions to the point that many scenarios put restrictions on how many Chaos units a player can have.
One very notable difference in AK compared to WK is in mobility. With the sole exception of the Chinese dragons, there are no flyers in Ancient Kings. The only Aquatics are ships and there are few Amphibians. Campaigns will play out along more conventional lines as far as approaches go. Whether this is a good thing or a drawback is a matter of taste. Things are likely to be a bit less free-wheeling than WK as a rule.
The role of clerics may at first seem to be a mere substitution for that of wizards, but that's misleading. There are some significant, if subtle, differences.
For one thing, clerics are not Flyers. They are more rare, on the whole, than wizards, on the counter sheets and you'll need to buy quite a few sets before you have more than a few.
Their Divine Rituals are generally similar to Wizard Spells. For example, The Chinese God Jurong Level 1 Ritual Spirit of Fire allows a 4 die attack at F2 with targeting allowed, whereas the Level 1 Orc Wizard Spell Fireball casts a 4 die attack at F2 with no targeting.
But Clerics don't have anything like a Henge for cheap rebuilding, so their spells are a little more costly. They are also a little harder to get off as well. While wizards in Wk come in two speeds. A+ and B+, all clerics are B# units. This means they can fight in a battle without casting spells, which is good, but it also means that an enemy army with a lot of A-speed units is going to get to act before the opportunity to invoke a ritual arises. So, while a defending Wizard in WK caught by a superior force gets a chance to do something to whittle down his foes, a Cleric in Ancient Kings will be ridden down and slaughtered instead.
The main thing lacking in Ancient Kings right now are scenarios suited to its nature. A handful of Wizard Kings scenarios from the scenario book downloadable from the Columbia Games Web site seem like they would work well for AK armies. Exxxtreme Conquest, Gold Train, Neutral Buffer Zone, Lost Relics, Sleeping Wyvern and Two Front War all seem playable with no changes. Many other scenarios can probably be adapted as well, but a few Ancient Kings specific scenarios would be a positive development.
So is Ancient Kings worth getting? Probably not if you're just looking for something to add to your Wizard Kings games. It doesn't really add anything you don't already have. Probably yes if you'd like to play a Wizard Kings style game that's a little less chaotic and random and more strategic. In most block games strategic play involves the execution of a plan over several turns and it is very hard to recover from being outwitted. Wizard Kings, because of the proliferation of flying units and the powers and ubiquity of magic users and chaos units can be more chaotic in play and less strategic. If you are out maneuvered in Ancient Kings, you won't be able to fly over a wizard leading a corps of pixies, dragons and hippogrifs to save the day.