The standard 15mm game is on a 120" x 80" board (sort of like Dbmm 200) with a 200pt army made up into 3 Corps/Commands.
The rules allow for smaller (100pt) or larger 300/400pt games on correspondingly larger table (300/400pt of a 'standard' 6' x 4').
Units are single Dbx sized bases of Cavalry or Light Infantry with other Foot being in 2 or 3 ranks (ie 2-3 standard Dbx bases) with moves being in UD (unit distance) which equates to Base Width ie just like Dbmm.
It uses a Pip type system but somewhat different Dbx.
You roll for each Commander adjust for his quality then halve to get Pips.
Group moves are allowed.
Unlike Dbx suitably armed units can shoot at 1-4 UD (1 for Javelins 2 for LI/LH/Cav Bow/Sling and 4 for foot Bow only units).
Units exchange shots in each others turn with a max of 1 Cohesion loss inflicted.
Units vary from 2 to 4 Cohesion.
Like Sword and Spear they die in place once Cohesion level lost with Rout tests for friends within 1 base.
Any unit with a Choesion hit additionally counts as Disordered
Again like Sword and Spear units can Rally off hits even in Melee but correspondingly easier the further you are from enemy.
Melee is based on a base hit factor then taking account of circumstances such as opponent type, armour classes, Impact, Impetus and the usual sorts of factors.
Units in Melee roll off against each other with loser taking hits based on level of defeat suffered.
Movement is well explained with options for group expansion, turns, charge moves and evades etc.
No real difference between Regular and Irregular troop types but this is shown in the overall Command levels of armies with good (mainly Regular) armies having level of 5-6 most others 3-4.
These command points allow purchase of several types of Commanders from Poor through to Brilliant with a corresponding effect on Pip rolls for their commands.
The Great Captains of history such as Hannibal or Alexander and suchlike can be purchased as Strategists with some additional benefits.
These heroic chaps are only available if listed in their Army listing.
The rules are nicely produced with a good smattering of examples throughout which is very helpful.
The rules also include terrain set up and deployment system and a huge list of armies with associated points costs/options covering from Summerian up to Mid Medieval periods and covering the vast bulk of armies (not quite as comprehensive as the 4 Dbmm lists but close and all in one volume).
I found brief test to be enjoyable with the rules falling in between Sword and Spear/Pulse of Battle and Dbmm/FOG in complexity.
Might be different case when playing bigger battles ?
Whilst they were fairly expensive (£25 + P&P) they compare well to Dbmm and FOG by being an all in one set.
I used Maurikian Byzantine versus Sassanid Persian and Byzantines have excellent Command level of 6 compared to Persian 4 allowing them to buy (Commander other than Ordinary types have a cost) good Command & Control as such.
A couple of quickly made up lists yielded 20 Byzantine units versus 26 Sassanid.
These unit levels are the Army Destruction level with a Routed unit counting as 2 and each Disordered/Left the table as 1, Camps lost count as 4 and lost Commanders vary by type.
Another set well worth exploring further.