NOTE - this applies to the time period before the effective mass deployment of gunpowder weapons, from the start of recorded history to the late medieval period (mid 1400's).
Although guns may have been widely used during the battles of The Hussite Wars (1419-34), they were only really effectively employed at the very end of the Hundred Years' War (1337-1453). For sure, at Formigny (1450), two primitive 'culverin'-type cannon were used by the French (who still lost the battle) to successfully break up the English massed longbow formations it was not until Castillon (1453) the French deployed over 300 gunpowder weapons which were the major factor in winning them the battle
What are the basic unit types ?
Essentially, Foot and Mounted. Ancient battles generally took place on land (with a few notable exceptions in the Mediterranean arena) with ships only really being employed in transport, supply and messenger roles. However, within the 2 main divisions, Foot and Mounted, there were numerous distinct variants.
The 'effectiveness' of Foot and Mounted differed greatly depending on which type they were facing. Archers, in particular, were weak against other Foot but very effective against Mounted. To 'map' this distinction across to CF Unit 'types', CF 'ground' = Foot which leaves us with CF 'ship' = Mounted (although there is no 'air' type in Ancient period, in CF air units count all terrain 'cost to enter' as '1', so we can't use 'air' as Mounted)
Foot varied from lightly armed skirmishers through to the heavily armoured and armed 'phalanx', with most foot soldiers being somewhere in between. Some sort of sword and shield was common for most types, even for those with other primary or ranged weapons. Most soldiers fought as groups, either by deliberate organisation (eg Roman Legions) or as an informal 'clan' or 'war-band' collective
Mounted troops varied depending on their 'mounts' - from those riding on the backs of Elephants, Camels & (more commonly) Horses to those carried in Chariots and War-Wagons - and in degree of armour, from essentially none (Hunnic horse archers) to fully enclosed (Knights)
Ranged weapons consisted of various types of bow, sling and spear, with a few specialist types (such as bolas and (Roman) darts). Sometimes it was as the primary weapon (English Longbows), sometimes a 'secondary' (Roman Pilum). Bolt and stone-throwing 'artillery' were typically slow moving, slow firing and restricted to sieges - although the Romans did employ massed (ballista) on the battle field, these were essentially just a scaled up cross-bow on a stand (and not to be confused with the larger siege version of the same name)
How was the 'typical' Ancient Army deployed ?
Since mounted always cost significantly more to arm and train than foot, the bulk of any Ancient Army would consist of the 'infantry' - and the usual approach would be to 'line-up' your forces opposite the enemy and then launch a simple frontal attack.
Since foot were always very vulnerable to mounted attack (some defences could be deployed (English Longbow stakes & spiked caltrops used from Roman times onward and the use of long spears & pikes (which were instrumental in winning the Battle of Bannockburn (1314) for the Robert the Bruce by forcing the English horse onto the Scots pikes) which could also deter a frontal attack), most armies depended on their own mounted troops to hold off those of the enemy (and prevent them attacking the flanks & rear of their own infantry).
If outnumbered or outclassed in mounted, unless they could gain some advantage from the terrain (the English at Agincourt, for example) the Ancient Commanders only real hope was to crush the enemy foot before the enemy mounted could return and crush them :-)
As a result, the 'classic' deployment consisted of 3 'commands', with the foot in the center and a group of mounted troops on each flank. The goal of most commanders was to crush the enemy center with their own foot, whilst their own mounted kept the enemy mounted off their flanks. About the only 'variation on the theme' was to hold back your own foot whilst your mounted defeated the enemy mounted and fall on the flanks & rear of the enemy foot - however this was risky since if the enemy rushed forward and defeated your own foot fast enough, the outcome of the mounted battles on the flanks would be irrelevant
The Romans seemed to take this to extreme, having relatively few mounted troops = what they did have was largely recruited from allies (which were always less reliable than your own troops)
What sort of tactics were employed ?
Typically both sides would deploy their troops, establish order and control (not easy when the main means of communication was restricted to 'line of sight' through a 'hierarchical' command structure) and then, when all their forces were 'in place', commence the battle based on some plan decided upon the previous night, well before the full details of the enemy forces where known for sure.
Communications (and understanding) were always a problem on the Ancient battlefield. The more complex the plan, the more likely some elements would fail to take place when or as intended. However the Army with a 'plan' was more likely to 'win' since it was almost impossible to 'react' quickly to enemy actions. So 'seizing the initiative' was always a key intention of any commander.
Before combat was joined, armies would send out skirmishers and use their long range weapons (bows, crossbows) to 'test' the enemy troops determination, (attempt to) break up their ordered formations and try to tempt them into making unwise charges. Those with the advantage of higher ground would often make such full use of their ranged weapons that the enemy had no choice but to launch a frontal attack uphill at a disadvantage (or die where they stood)
Of course if they expected to win the mounted battle(s) on their flank(s), a canny commander would 'refuse' their center until their victorious mounted troops could fall on the flanks (or rear) of the enemy. Those expecting to loose a mounted battle, but who had 'advantage of ground' (for example, by being uphill or deployed between terrain features impassible to mounted - the English at Hastings or Agincourt, for example) might choose to hold their ground and temp the enemy mounted into frontal attacks or otherwise attack in a way that their own mounted would gain some advantage (such as bow fire support from their own foot)
Of course 'advantage of ground' could easily be thrown away if the enemy could temp the 'defending' troops into making unwise charges away from their own lines and into the enemy grounds where they could be cut down piecemeal (such as the Anglo-Saxons at Hastings)
Commanders with few mounted troops and no advantage of ground would have little option but the charge the enemy at the first opportunity - and hope to win before the enemy mounted was able to make a difference. This was the only real option for most tribal 'war bands' (such as the Gauls, ancient British and Scots)
NB. You might think that the Romans would fit into this category - having few mounted troops of their own (although later Roman Armies did employ mounted allies). Fortunately (for the Romans) their main enemy consisted of barbarian war-band 'hordes' who also lacked any organised mounted troops. As a result, they could choose weather to attack or wait, or (the more normally Roman tactic) march slowly forward in 'good order' until the enemy was tempted into making an unwise (chaotic) charge. Even those with a mounted arm - such as ancient British chariots - could still be counted on to behave like any rampaging mob and run (or ride) screaming and shouting at the solid Roman shield interlocked armoured troops front line, where they would (generally) be chopped to pieces and trodden underfoot as pressure from their own rear ranks forced them onto the Roman swords (and under the Roman hob-nailed boots), much as happened at the Battle of Watling Street (AD61) (which put an end to Boudica's revolt)
Movement speed in the Ancient period
I ended up with 1 hex = 50 yards. This gave me basic values for bow fire = 6 hex's, heavy foot movement = 4 hex's per turn, foot = 6, heavy mounted = 8, mounted = 10, scouts = 12 (specific units have slightly different moves and ranges)
I started with 1hex = 100yds, but this made the game very slow (or the two opposing armies have to start so close together that there is no time for any 'maneuvering into position'). Slow movement allowances also makes small adjustments for the effect of terrain impossible
What effect does terrain have ?
Unlike during the mechanised warfare period, in the ancient world terrain had a major impact on both movement and combat
Hills gave a huge advantage to the army that held them, it being much harder to attack up-hill. The higher ground also made a significant difference to the range of bow fire etc. and could even (steep hills) allow you to deploy your archers for 'indirect' fire (over the heads of friends in the front line) at an enemy who not only could not see who was firing at them but, even if they could, their bows would have insufficient range to fire back
In fact, even when all other things were not equal, the forces holding the higher ground could nearly always force a stalemate, even if not an outright win - simply by standing were they were and fighting off all-comers (English at Battle of Hastings before the unwise breaking of their 'shield wall' to pursue the Norman mounted who were feigning a retreat (or fleeing - reports differ) downhill and then getting slaughtered at the bottom by fresh Norman forces)
CF Terrain Tile definitions have 'attack' / 'defense' modifiers, but no provision for 'range' adjustment
Marsh, woods, streams and other obstacles had a really significant effect on movement, especially for mounted troops, reducing them to the same or even slower speed than foot and eliminating their mounted combat advantage.
Indeed, even a muddy field could mean death for mounted troops (French Knights at Agincourt) and mud/marsh has an adverse effect the route taken by attacking foot (Macdonalds charge at Culloden). Needless to say, Chariots were even more vulnerable to obstacles than horses (which does make you wonder why the ancient Britons hung onto them for so long in the wildly wooded ancient English countryside)
If the battlefield was near a river, the question of who held the bridge(s) or ford(s) could make the difference between outflanking or being outflanked (and thus determine the winner) and the difference between escape or annihilation (for the looser).
Needless to say, getting caught with half your army on the 'wrong' side of a river was always a receipt for disaster (Vikings at the Battle of Stamford Bridge)
Mountains were essentially impassible (Hannibal not withstanding :-) )
A few troops defending a pass (or the shore between mountains and sea) could hold up an entire army (see, for example, Thermopylae)