A regular has asked for a full review, and after several games of Hail Caesar, I feel in a position to actually enter onto the same.
So essentially we have here a two hundred page hard back rulebook, in lavish colour throughout, as is the way these days. The mechanics of the rules are probably about half of this , and are clearly presented and well explained with plenty of diagrams. After one or two reads, play can largely be conducted from the 9 page summary at the back of the rules.
So how do these rules shape up against other systems, how do they work. Well , my previous experience includes Warhammer, Armati and DBM so I will reference these as I see fit. HC shares aspects of some of these rules, but is largely different from all of them, and any similarity is likely to be coincidental.
The core mechanic is based on Black Powder, which in turn was descended from Warmaster, perhaps Games Workshops best (if still imperfect) set of rules. Formations of troops are grouped together to form 'divisions' within an army, and each division is led by a General - one of which is identified as commander in chief. Units do not have casualties removed, rather they are marked in some way during the game to show losses. Therefore single figures are not essential, though multiple bases for a unit are valuable to represent formation changes. Figures based for DBM would work perfectly with this. The rules recommend basic unit sizes of 16-24, though we have found units of 12-16 to be perfectly satisfactory.
Units move by being given orders, an order being a clearly defined instruction announced by the commander to the opponent(s); such as," the Saxon Thegns will advance around the wood to their left to turn the flank of the Norman line". two d6 are then rolled against the command value of the general. the result allows 1 to 3 actions in the event of a success, or may fail, or even result in a blunder (a random move, usually with undesired results!). Fail and you stop issuing orders with that commander; though the commander in chief has the right to order one re-roll per turn.
Whilst players often overstretch themselves at first with this mechanic, a few games teach you that restraint is wiser, otherwise there is a good chance troops will be left hanging or lagging behind. Two other points are that units can move of their own accord once within 12 inches of the enemy; but once they are,they have to align to the nearest enemy and can no longer try clever moves. This ensures tighter battlelines.
The resultant tendency to maintain formations and fight in a clear battleline has more in common with Armati and DBM than Warhammer, which always looks like a Hollywood battle once a round or two of combat has occurred.
Shooting and combat are similar to Black Powder, but with a slant to hand to hand, units typically role 2-3 dice in shooting or 4-9 dice in hand to hand. The default being 4+ to hit, in combat both sides roll dice, and in either case, any hits may be reduced by a morale roll (identical to the Save roll in Warhammer). This is closest to Armati of the three other systems. Warhammer is buckets of dice by comparison, whilst DBM is on the fall of one D6 and a load of obtuse modifiers.
Units can take a limited number of hits, but these in themselves do not destroy a unit, until double their value are suffered, rather break tests are taken either when a unit loses a round of combat (suffers more hits than it's opponents) or has sixes rolled against it by shooting. The lower the roll on 2d6 the worse the result. The tables are subtly progressive.
There are two major additions to combat, supporting units add a small number of dice to melee, as does a general. However any general joining a combat will risk death or injury. This again swings the game more in line of Armati, but has a similar effect to the modifiers in DBM. One other point to make is that some units have higher combat values in the first round of a melee than in later ones. Representing the impetus of an aggressive charge.
As with BP, units can be varied by special abilities or weapons, and a range of sample units are presented. Along side this the second half of the book provides seven scenario's and therefore 14 sample armies covering two and a half millennia.
To summarise then, you have a set of rules that manage within the core to provide a good representation of the tactical limitations of the period, but with allowance for more flexibility than DBM/Armati without throwing reality out the window, like Warhammer. The size of formations can be scaled up or down to suit the demands of the players, and with smaller formations works perfectly on a 6 by 4 foot table, far better than Black Powder did.
In general the rules benefit from being effectively a second edition of the core rule system, honed and clearer, giving a better game than BP - which was already pretty good. With the advent of a supplement of pointed army lists, it is clear that casual and competition play, always popular with ancient gamers, will be accommodated.
Of course, the rules again expect gentlemanly conduct and fair play; not resorting to lawyerly precision to avoid disputes, favouring mutual agreement. We all know at least one player this will not work with, and the rules will often only be as good as the umpire if scenarios or re-fights are being played. Still with those proviso's I would say that these are simply the best set of rules for ancient games I've played in twenty years. And I cannot see me returning to any of the other mentioned systems, any time soon.
There is a mass of options and other material to explore in what is a comprehensive and attractive package. Why look anywhere else?