I like to write every so often both for fun (I'm such a nerd), and writing a guide often reminds me of how to be a better war maker. I of course encourage the strong warring players of the forum to critique the work.
Note on Promotions from both lines: I do have a section for promotions that exist on both lines AND have equal access on both sides. However, the promotions that come early in one line I assign to that line, as I generally find that is where it gets used.
Infantry
Drill Line
Drill is a great early promotion for those engaging in ancient/classical era warfare. Infantry with a strong drill promotion can do well against even walled cities. Around Medieval, the arrival of castles and strong mounted challengers means the infantry city taker takes a back city to siege, and I tend to forego drill at this time.
Drill then sees a resurgence around the Fusilier stage. Infantry gain a solid overall boost at this point, and with the ability to generate City Assault infantry at will, drill becomes more useful again.
Newbie Note: One mistake a lot of new players make. The bonus from drill does not protect your troops from city ranged attacks. If you need a unit to stand there and take city hits, cover is a much better promotion to use.
Another note, new players using Drill may get frustrated that their infantry are just not doing the job against cities, thinking the promotion is bad. The trick is you really need Drill III or CA before infantry become very effective against walled cities. This may require bouts of attacking and retreat + healing until you have the necessary experience. However, once you have several infantry with those higher promotions, you will see a big power boost in your ability to take early cities.
Amphibious City Assault
One of the best tricks I use in later game warfare. I will put Drill II City Assault infantry in the water, and have them attack the city there while protected by a melee naval unit. This removes one of the biggest weakness of CA infantry, which is the return fire from mass ranged units. While you do suffer the -50% amphibious penalty, I find the 33% hp saving from CA generally makes up for it (and you can pick up amphibious as your 4th promotion). You can have the infantry attack at will, and then swap them out as their hp run down.
Using infantry this way can double the strength of your amphibious assault.
Drill III vs City Assault
Early game I will almost always go CA, as that is the reason I am taking drill in the first place. A bit later on, it will depend on where my troops are still attacking the units or if I am in the city assault stage. And of course if I'm pushing more into the medieval phase I will go drill III and then prepare for better late game promotions for my infantry, as CA is a bit of a waste during the castle period.
Cover
This is a solidly good all around promotion. In the early game, its a good promotion to use against enemies fielding heavy ranged armies (Babylon being a good example).
Cover really comes into its own by Industrial Era with the arrival of gatling guns. At this point, cover often becomes an essential promotion for your frontline Fusiliers/Rifleman to hold out against the wave of g guns/bombers/artillery that follows during this era. I often will make my new infantry with Drill + Cover 2, and then promote my older veterans into the "cooler" promotions.
I also often use cover for my citadel infantry if I've set up the citadel so that its mostly ranged attackers that will hit me.
Lastly I use cover quite heavily in later game amphibious assaults, and this is generally the promotion I use for infantry first hitting the beach. A cover II infantry can take a tremendous amount of punishment, which you need to start getting a foothold in enemy territory connected by railroads.
Formation (often just Formation II)
Often a solid early promotion when you have a spear unit that you just need to hold a flat piece of ground, as Formation II can get it a solid defensive advantage. That said, I generally don't find the +5% extra CS a real advantage compared to more drill or shock....so I would only get formation to take on mounted units or if I know that this unit is going to be a defender its whole life. For more general spears I will stick with Formation I and then promote on the normal lines.
Blitz vs Stalwart
When you do hit your Tier IV level, often its a debate between these promotions.
In general, I favor Stalwart for infantry. Even for city takers later in the game, I find the ability to hold a position more valuable than the extra damage Blitz can bring. Stalwart is also a good "save my bacon" promotion, if your infantry gets hit hard and you get a promotion, the healed Hp + extra defense can be the difference between saving the unit and losing it.
Blitz's best use is often when you have a military tech lead over your opponent, and so can stomp over his troops with your superior ones. To get the best use, you need to pay attention to ZoC, and so blitz often combines well with units like Musketeers or Autocracy players using lightning warfare. Blitz can also be useful in more open scenarios, where you have the ability to attack once, and then move back. Often this is far more useful than attacking twice, as the double attack can leave you too damaged to survive the return fire.
Shock Line
Shock is the more general infantry line, so its often more the default promotion if you don't have a strong need for drill. Shock tends to increase in strength in the medieval era, as armies become larger flanking chances increase, and drill tends to be weaker at this stage in the game. In the later game shock is a good line for your more general troops that don't have specialty needs (or you don't need cover promotions for).
Amphibious
Amphibious is the promotion I often chide myself for not using more often. Early game, rivers are often a major pain in the butt, point crossing in your own territory until you have roads and bridges, but can be the strongest defensive bonus your enemy has. The ability to gain bonuses when crossing rivers is huge, but often more important, is the ability to retreat across them when you are wounded....which will save you units that otherwise would have just died to counterattack.
Later game, Amphibious is useful for.....Amphibious Assaults! The best use of this is when the enemy is trying to hold off your navy with ranged/skirmisher/and siege weaponry. Protect your unit with a naval unit, and then have them attack the beach from the sea. This can often disrupt enemy land units, and give your naval units a much needed reprieve from land bombardment. However! Don't finish land units off with Amphibious units if you can avoid it (this puts them on the beach with no naval protection and ill suited promotions). Instead finish the unit with naval bombardment, and then send Cover infantry onto the beach, which are much better at absorbing the inevitable counterattack.
Medic
Ranged units are MUCH better at being medics. Only use the melee medic promotion if you are absolutely desperate, otherwise this is a waste.
Woodsman
In general, this is a niche promotion but in the right circumstances can be very useful. You'll want to use this against enemies in large amounts of rough terrain (such as forest or jungles). In those cases, the ability to move twice in rough terrain can be a godsend, both in getting to your enemy, but in your enhanced ability to retreat.
March
I find March one of the strongest and yet trickiest promotions. Often early on when I started using it, it would just get my units killed more often than it helped. It took a lot of practice to really make march units shine.
First, a march unit MUST always be accompanied by a Medic (preferably Medic II) ranged unit. Otherwise you are missing out on the main benefit of the ability. With that in mind, it can often be best to attack with the march unit first. That way you don't finish the enemy and the march unit doesn't move out of range, and then you use the ranged units to finish the job.
March is often best for units staying in your own terrain, as they get the most healing benefit and tend to suffer fewer counterattacks. Put them one hex from your border, and have them attack units that enter your territory. The best terrain is to put them right behind rough terrain. As enemy infantry moves in (but doesn't get to attack due to the rough terrain), the march infantry can counterattack, and heal all of the damage suffered. This can be a major force multiplier when lines of infantry are squaring off against each other.
March can also be a great citadel promotion. If your citadel is not too exposed to ranged fire (otherwise cover is often better), a march unit can attack from the citadel with impunity, staying in tip top shape while delivering good damage to the enemy force.
A good "emergency" use for march is when you finish attacking in place but now need to move to another area of your civ (such as do to a recent war declaration). In this scenario I may promote a few more march units than I might have otherwise, as I would rather have my infantry be at full health as they move over to the new area, instead of forcing turns of healing while the enemy begins their attack.
Overrun
A properly flanking Overrun infantry can actually generate some of the highest CS numbers in the game. While the 10 splash damage is cool and a lot of fun to use....honestly splash Siege weapons I find will deliver splash more consistently than overrun infantry.
No, the real prize is the +25% flanking bonus. Overrun infantry is best used with "protrusions" in the enemy line. If you are just lined up equally with the enemy, neither side is getting flanking bonuses, and overrun goes to waste. However, if you find those spots where the enemy is pushed out against you a bit more, you can often get a two unit flank on them, which is an extra +50% with overrun.
Similar to March, overrun units don't work well alone. You should always have a couple of flankers with such a unit at all times, and of course a squad of 3 units all with overrun can often rip through any other unit an enemy can throw at you.
Cross Line Promotions
Air Defense
Honestly I almost never use this promotion, as you need to use it a lot in order to deter air attacks, as otherwise the enemy will just find other targets to hit with their aircraft, and then this promotion does nothing. I would only recommend it if the enemy has absolute air dominance over you, and your infantry are just getting shredded by bombers.
Ambush
Another promotion I rarely use. Its a more niche promotion but requires Tier IV, making it tricky. Obviously if your getting assaulted by large tank numbers (aka playing against Germany), then it make sense to use. The rough terrain attack promotion I don't find strong enough compared to just taking Shock I or another Tier IV, so its really only seeing use if I really need an anti-tank counter.
Mobility
Mobility can be a good general promotion if you don't need any specialization at the moment, as a +1 movement can be useful in lots of scenarios. You double your speed in hilly terrain, which can be a lifesaver in the right circumstances.
That said, I tend to use mobility sparingly, as I am already using mounted units/tanks in areas where I need the speed. Its less that I choose to use mobility, and more other promotions are just not the right fit, and so I use this as a nice solid option that will work no matter the conditions.
Newbie Note: It can be tempting to use mobility as a "bail out" promotion. Aka your infantry is about to die, and can't get away with its two speed. So you could be tempted to take mobility, as 1 more speed is all you need to live! But note that you do NOT get the bonus when you first take the promotion, only 1 turn later....so this is a TERRIBLE bailout promotion!
Ranged
Accuracy Line
The majority of your ranged units will likely use accuracy. Because of the nature of combat, more of your attacks will occur against healthy units than ones below 50% HP, and attacks made here are more likely to use the full damage value, whereas attacks on severly wounded units might kill them regardless of promotions. For that reason, you should use accuracy for the vast majority of your ranged units.
Medic
Honestly, probably one of the most important promotions in the game for the human player, and one I think a lot of newer players don't use nearly enough. The ability to recover damage more quickly is critical to any sustained warfare, which at higher difficulties is all warfare.
There are several scenarios where you want to have medics handy.
1) Behind your front line. As your front line infantry takes damage, having medics right behind them increases their longevity. You especially want this in a hot zone like a citadel that is taking a lot of damage.
2) Healing "centers". As a war drags on, more of your units will get hurt and need healing. While at first, you can just use those front line medics, but eventually you will need more than that. Having a medic farther back to set up a "field hospital" will ensure access to healing for all of your units. Always have enough medics to heal all of your troops.
3) Planes and Cities: As aircraft become available don't forget to station a medic near the city where your bombers are stationed. This will ensure rapid healing and redeployment as needed.
Range
So its not a question of when to take range. Range is one of the strongest promotions in the game. It makes your units safer, as they can outrange common archery units. It makes them stronger as you can now focus more units on the same target. And it lets you attack in scenarios you couldn't attack from otherwise. Range is just amazingly good, and its one of the true force multipliers in the game. The attack penalty is a pittance in comparison.
So in general with accuracy promotions, its really "Ok I'm getting range at 4th, what am I getting at 5th?" That said, there are a few corner cases where you might consider not getting range right away.
1) You are in really rough terrain with few hills. If your fighting in an area where there are just no hills and tons of rough terrain, range won't help you, and some other promotion might be more useful.
2) Front line unit. Later in the game as G guns and machine guns can be front line units, you may find yourself in a situation where you can't pull the unit back to make use of the range, and so just want to apply damage right now. In that case you might delay range for a time.
Indirect Fire vs Firing Doctrine
So after range of course, which promotion to take depends on what terrain you find yourself in. Having 3 range means that vision blocks occur even more often, and so having a completely clear 3 range unit that can literally hit anything it wants is extremely good, and is a good case for indirect fire.
That said, don't get indirect fire automatically. Its an effectively -35% damage compared to taking Firing Doctrine (at least against healthy units), and that is nothing to sneeze at. So if the ranged unit is a defender on a good hill for example, indirect fire may not be necessary right away. Firing Doctrine does add a good bit of damage, so if your fighting in more open terrain or already have good hills to use, take it first, and only consider indirect fire later as the terrain changes.
Barrage Line
Barrage can be a tricky promotion to make full use of, and even I tend to overmake accuracy just because I don't want to think about it.
One of the simplest ways to use it as in a fortified scenario. For example, on your front line you have it set up where as the enemy unit comes in it will take 3 shots from your ranged units. So you set up the first two on the left with accuracy, and the 3rd on the right with barrage. And then just get in the habit of going left to right with your ranged attacks. This allows you to use the promotion without thought.
Do note that depending on how sturdy the units are, you may need to do a 2 accuracy to 1 barrage or 3 accuracy to 1 barrage set up. If your accuracy units are doing ~30ish damage, you can use the first scenario, if your down in the 20s best to use a 3 to 1.
Cover
I use cover sparingly for ranged units, as your goal is to get them highly promoted into those force multiplying promotions.
If your near city areas, and the city is strong enough, you may need cover to survive some of the bombardment. Or if you find yourself in archery duel commonly, technically a cover archer is a little bit better than an accuracy one (though its not a big difference).
So cover is more a promotion you "have" to use to survive the current conditions, instead of one you want to use.
Logistics
Similar to range, this is your major force multiplier, and so should be your default Tier IV promotion. It also generates XP more quickly, so even if another promotion might be slightly better in a circumstance, I still normally get logistics so I can more quickly get to the other one.
Indirect Fire
Not as useful as compared to the accuracy line, as with 2 range you get blocked less than with 3. Also with the -30% from logistics, remember that every additional attack penalty hurts a little bit more. I will often consider going Accuracy I or Infiltrators unless I am really in a scenario where I need to remove the blocks.
Infiltrators
This is a weird promotion but properly used gives a very large bonus. Honestly the -15% for being near another unit I would ignore, if you can get your unit alone than great but the penalty is not that big compared to the rest of the promotion and I would never hurt my line formations for the bonus.
So this promotion is used for ranged units that you are pushing into enemy territory, as opposed to your defender units that bombard enemies coming into your borders. As long as you make sure its the 2nd ranged unit to attack, you are looking at a full +35% attack bonus even with that -15%.....the best boost you can get.
I don't get this promotion a lot, and of course only after indirect fire, but the combination of this promotion + logistics can really murder units.
Mounted Melee / Armored
Drill Line
In general, mounted units are not great city takers and tend to be more "offensive" than standard infantry. So drill tends to be a weaker promotion line for them.
That said, some horse UUs like Songhai's Mandekulu or Byzantium's Cataphract are much better city takers than normal, and so can be equipped with drill for quick city assaults.
In this cases, the horse is best served by attacking the city and pulling back, which reduces the ranged fire they take and grants them increased longevity.
Now once the armored units come into play, drill also increases in strength, as armored units are strong enough to still be good city takers even with their penalties.
Sentry
Vision is very important, but if I need it I generally use the scout line to provide it, as that is literally their job. As such I almost never use this promotion, if I'm spending horses on a unit, I want its promotions to be meaty.
Stalwart
Often I have these units dive in to finish a unit off, so anything that lets me survive the counterattack better is a solid gain. This is still a solid promotion.
Blitz
While blitz is not great on infantry it can be very solid with mounted units. The main reason is pillage. A mounted unit can attack a city, pillage a tile or maybe 2, and then attack again....mitigating the "double damage". This is especially true with tanks that have high movement and so can often pillage a few times.
Mobility
More speed is always useful, it lets you reach deeper with your horses, pillage more if your doing a run in enemy territory, and cross 3 rough terrain tiles before tanks. This is my default Tier IV if I'm going drill and I haven't yet gotten tanks. With tanks, I generally consider blitz more strongly.
Formation
Unless you have a UU like the winged hussar that starts with formation, I wouldn't generally pick this up. Your not going drill on a horse unit to make it better against other horses, I would rather just take shock for that normally.
Shock Line
Mounted units are great flankers, able to move in to provide flanks and move out again as needed. So the shock line tends to get a lot of use for mounted melee.
Charge
Charge is my default promotion for mounted melee and I rely on it heavily. I find it often crosses the threshold between severely hurting a unit and killing it outright. As I often use mounted melee to snipe key siege or ranged units, this can be critical. And Charge II is murderous on how much extra damage it can generate.
Later game, charge combines very well with Splash Siege, as even just a 5 HP wound is enough to trigger charge.
Overrun vs Mobility vs March
As I said, Charge and Charge II are my common promotions, so I only go Shock III into these promotions very sparingly.
Ultimately I don't use mobility much in these scenarios, march and overrun are both just very good force multipliers. March is great on horses that can run in and attack, and pull back to a medic (or even better a city with a medic for some real healing). Overrun gets a lot of use as flanking is so common for horses and they tend to be offensive.
So ultimately its more preference than tactics at this point if your using these promotions.
Skirmisher
Accuracy vs Barrage
Ultimately I do not think Barrage is a good promotion line for skirmishers. Logistics is weakened because skirmishers prefer to dart in and out quickly, consuming 2 movement to attack is not ideal. Accuracy is generally better than barrage on base stats, and unless you are making tons of skirmishers I think its better to make them all accuracy.
Parthian Tactics
I consider this the default skirmisher promotion. When using skirmishers, the major question is always "can I get to an open terrain spot and get out safely?". As such extra movement is hugely beneficial. And the lack of ZoC can also open up opportunities for attack you may have not had otherwise. It is rare that I do not take this promotion first.
Firing Doctrine
A solid Tier V after Parthian, I will sometimes take it first if I'm using my skirmishers defensively and I know I will be doing the same attack routine for a while and don't need the extra movement.
March
March is not a good promotion for you here. Skirmishers used properly should not be taking hits, and when they do they already take a lot of damage, the defense penalty from march could get your unit killed.
Note on Promotions from both lines: I do have a section for promotions that exist on both lines AND have equal access on both sides. However, the promotions that come early in one line I assign to that line, as I generally find that is where it gets used.
Infantry
Drill Line
Spoiler :
Drill is a great early promotion for those engaging in ancient/classical era warfare. Infantry with a strong drill promotion can do well against even walled cities. Around Medieval, the arrival of castles and strong mounted challengers means the infantry city taker takes a back city to siege, and I tend to forego drill at this time.
Drill then sees a resurgence around the Fusilier stage. Infantry gain a solid overall boost at this point, and with the ability to generate City Assault infantry at will, drill becomes more useful again.
Newbie Note: One mistake a lot of new players make. The bonus from drill does not protect your troops from city ranged attacks. If you need a unit to stand there and take city hits, cover is a much better promotion to use.
Another note, new players using Drill may get frustrated that their infantry are just not doing the job against cities, thinking the promotion is bad. The trick is you really need Drill III or CA before infantry become very effective against walled cities. This may require bouts of attacking and retreat + healing until you have the necessary experience. However, once you have several infantry with those higher promotions, you will see a big power boost in your ability to take early cities.
Amphibious City Assault
One of the best tricks I use in later game warfare. I will put Drill II City Assault infantry in the water, and have them attack the city there while protected by a melee naval unit. This removes one of the biggest weakness of CA infantry, which is the return fire from mass ranged units. While you do suffer the -50% amphibious penalty, I find the 33% hp saving from CA generally makes up for it (and you can pick up amphibious as your 4th promotion). You can have the infantry attack at will, and then swap them out as their hp run down.
Using infantry this way can double the strength of your amphibious assault.
Drill III vs City Assault
Early game I will almost always go CA, as that is the reason I am taking drill in the first place. A bit later on, it will depend on where my troops are still attacking the units or if I am in the city assault stage. And of course if I'm pushing more into the medieval phase I will go drill III and then prepare for better late game promotions for my infantry, as CA is a bit of a waste during the castle period.
Cover
This is a solidly good all around promotion. In the early game, its a good promotion to use against enemies fielding heavy ranged armies (Babylon being a good example).
Cover really comes into its own by Industrial Era with the arrival of gatling guns. At this point, cover often becomes an essential promotion for your frontline Fusiliers/Rifleman to hold out against the wave of g guns/bombers/artillery that follows during this era. I often will make my new infantry with Drill + Cover 2, and then promote my older veterans into the "cooler" promotions.
I also often use cover for my citadel infantry if I've set up the citadel so that its mostly ranged attackers that will hit me.
Lastly I use cover quite heavily in later game amphibious assaults, and this is generally the promotion I use for infantry first hitting the beach. A cover II infantry can take a tremendous amount of punishment, which you need to start getting a foothold in enemy territory connected by railroads.
Formation (often just Formation II)
Often a solid early promotion when you have a spear unit that you just need to hold a flat piece of ground, as Formation II can get it a solid defensive advantage. That said, I generally don't find the +5% extra CS a real advantage compared to more drill or shock....so I would only get formation to take on mounted units or if I know that this unit is going to be a defender its whole life. For more general spears I will stick with Formation I and then promote on the normal lines.
Blitz vs Stalwart
When you do hit your Tier IV level, often its a debate between these promotions.
In general, I favor Stalwart for infantry. Even for city takers later in the game, I find the ability to hold a position more valuable than the extra damage Blitz can bring. Stalwart is also a good "save my bacon" promotion, if your infantry gets hit hard and you get a promotion, the healed Hp + extra defense can be the difference between saving the unit and losing it.
Blitz's best use is often when you have a military tech lead over your opponent, and so can stomp over his troops with your superior ones. To get the best use, you need to pay attention to ZoC, and so blitz often combines well with units like Musketeers or Autocracy players using lightning warfare. Blitz can also be useful in more open scenarios, where you have the ability to attack once, and then move back. Often this is far more useful than attacking twice, as the double attack can leave you too damaged to survive the return fire.
Shock Line
Spoiler :
Shock is the more general infantry line, so its often more the default promotion if you don't have a strong need for drill. Shock tends to increase in strength in the medieval era, as armies become larger flanking chances increase, and drill tends to be weaker at this stage in the game. In the later game shock is a good line for your more general troops that don't have specialty needs (or you don't need cover promotions for).
Amphibious
Amphibious is the promotion I often chide myself for not using more often. Early game, rivers are often a major pain in the butt, point crossing in your own territory until you have roads and bridges, but can be the strongest defensive bonus your enemy has. The ability to gain bonuses when crossing rivers is huge, but often more important, is the ability to retreat across them when you are wounded....which will save you units that otherwise would have just died to counterattack.
Later game, Amphibious is useful for.....Amphibious Assaults! The best use of this is when the enemy is trying to hold off your navy with ranged/skirmisher/and siege weaponry. Protect your unit with a naval unit, and then have them attack the beach from the sea. This can often disrupt enemy land units, and give your naval units a much needed reprieve from land bombardment. However! Don't finish land units off with Amphibious units if you can avoid it (this puts them on the beach with no naval protection and ill suited promotions). Instead finish the unit with naval bombardment, and then send Cover infantry onto the beach, which are much better at absorbing the inevitable counterattack.
Medic
Ranged units are MUCH better at being medics. Only use the melee medic promotion if you are absolutely desperate, otherwise this is a waste.
Woodsman
In general, this is a niche promotion but in the right circumstances can be very useful. You'll want to use this against enemies in large amounts of rough terrain (such as forest or jungles). In those cases, the ability to move twice in rough terrain can be a godsend, both in getting to your enemy, but in your enhanced ability to retreat.
March
I find March one of the strongest and yet trickiest promotions. Often early on when I started using it, it would just get my units killed more often than it helped. It took a lot of practice to really make march units shine.
First, a march unit MUST always be accompanied by a Medic (preferably Medic II) ranged unit. Otherwise you are missing out on the main benefit of the ability. With that in mind, it can often be best to attack with the march unit first. That way you don't finish the enemy and the march unit doesn't move out of range, and then you use the ranged units to finish the job.
March is often best for units staying in your own terrain, as they get the most healing benefit and tend to suffer fewer counterattacks. Put them one hex from your border, and have them attack units that enter your territory. The best terrain is to put them right behind rough terrain. As enemy infantry moves in (but doesn't get to attack due to the rough terrain), the march infantry can counterattack, and heal all of the damage suffered. This can be a major force multiplier when lines of infantry are squaring off against each other.
March can also be a great citadel promotion. If your citadel is not too exposed to ranged fire (otherwise cover is often better), a march unit can attack from the citadel with impunity, staying in tip top shape while delivering good damage to the enemy force.
A good "emergency" use for march is when you finish attacking in place but now need to move to another area of your civ (such as do to a recent war declaration). In this scenario I may promote a few more march units than I might have otherwise, as I would rather have my infantry be at full health as they move over to the new area, instead of forcing turns of healing while the enemy begins their attack.
Overrun
A properly flanking Overrun infantry can actually generate some of the highest CS numbers in the game. While the 10 splash damage is cool and a lot of fun to use....honestly splash Siege weapons I find will deliver splash more consistently than overrun infantry.
No, the real prize is the +25% flanking bonus. Overrun infantry is best used with "protrusions" in the enemy line. If you are just lined up equally with the enemy, neither side is getting flanking bonuses, and overrun goes to waste. However, if you find those spots where the enemy is pushed out against you a bit more, you can often get a two unit flank on them, which is an extra +50% with overrun.
Similar to March, overrun units don't work well alone. You should always have a couple of flankers with such a unit at all times, and of course a squad of 3 units all with overrun can often rip through any other unit an enemy can throw at you.
Cross Line Promotions
Spoiler :
Air Defense
Honestly I almost never use this promotion, as you need to use it a lot in order to deter air attacks, as otherwise the enemy will just find other targets to hit with their aircraft, and then this promotion does nothing. I would only recommend it if the enemy has absolute air dominance over you, and your infantry are just getting shredded by bombers.
Ambush
Another promotion I rarely use. Its a more niche promotion but requires Tier IV, making it tricky. Obviously if your getting assaulted by large tank numbers (aka playing against Germany), then it make sense to use. The rough terrain attack promotion I don't find strong enough compared to just taking Shock I or another Tier IV, so its really only seeing use if I really need an anti-tank counter.
Mobility
Mobility can be a good general promotion if you don't need any specialization at the moment, as a +1 movement can be useful in lots of scenarios. You double your speed in hilly terrain, which can be a lifesaver in the right circumstances.
That said, I tend to use mobility sparingly, as I am already using mounted units/tanks in areas where I need the speed. Its less that I choose to use mobility, and more other promotions are just not the right fit, and so I use this as a nice solid option that will work no matter the conditions.
Newbie Note: It can be tempting to use mobility as a "bail out" promotion. Aka your infantry is about to die, and can't get away with its two speed. So you could be tempted to take mobility, as 1 more speed is all you need to live! But note that you do NOT get the bonus when you first take the promotion, only 1 turn later....so this is a TERRIBLE bailout promotion!
Ranged
Accuracy Line
Spoiler :
The majority of your ranged units will likely use accuracy. Because of the nature of combat, more of your attacks will occur against healthy units than ones below 50% HP, and attacks made here are more likely to use the full damage value, whereas attacks on severly wounded units might kill them regardless of promotions. For that reason, you should use accuracy for the vast majority of your ranged units.
Medic
Honestly, probably one of the most important promotions in the game for the human player, and one I think a lot of newer players don't use nearly enough. The ability to recover damage more quickly is critical to any sustained warfare, which at higher difficulties is all warfare.
There are several scenarios where you want to have medics handy.
1) Behind your front line. As your front line infantry takes damage, having medics right behind them increases their longevity. You especially want this in a hot zone like a citadel that is taking a lot of damage.
2) Healing "centers". As a war drags on, more of your units will get hurt and need healing. While at first, you can just use those front line medics, but eventually you will need more than that. Having a medic farther back to set up a "field hospital" will ensure access to healing for all of your units. Always have enough medics to heal all of your troops.
3) Planes and Cities: As aircraft become available don't forget to station a medic near the city where your bombers are stationed. This will ensure rapid healing and redeployment as needed.
Range
So its not a question of when to take range. Range is one of the strongest promotions in the game. It makes your units safer, as they can outrange common archery units. It makes them stronger as you can now focus more units on the same target. And it lets you attack in scenarios you couldn't attack from otherwise. Range is just amazingly good, and its one of the true force multipliers in the game. The attack penalty is a pittance in comparison.
So in general with accuracy promotions, its really "Ok I'm getting range at 4th, what am I getting at 5th?" That said, there are a few corner cases where you might consider not getting range right away.
1) You are in really rough terrain with few hills. If your fighting in an area where there are just no hills and tons of rough terrain, range won't help you, and some other promotion might be more useful.
2) Front line unit. Later in the game as G guns and machine guns can be front line units, you may find yourself in a situation where you can't pull the unit back to make use of the range, and so just want to apply damage right now. In that case you might delay range for a time.
Indirect Fire vs Firing Doctrine
So after range of course, which promotion to take depends on what terrain you find yourself in. Having 3 range means that vision blocks occur even more often, and so having a completely clear 3 range unit that can literally hit anything it wants is extremely good, and is a good case for indirect fire.
That said, don't get indirect fire automatically. Its an effectively -35% damage compared to taking Firing Doctrine (at least against healthy units), and that is nothing to sneeze at. So if the ranged unit is a defender on a good hill for example, indirect fire may not be necessary right away. Firing Doctrine does add a good bit of damage, so if your fighting in more open terrain or already have good hills to use, take it first, and only consider indirect fire later as the terrain changes.
Barrage Line
Spoiler :
Barrage can be a tricky promotion to make full use of, and even I tend to overmake accuracy just because I don't want to think about it.
One of the simplest ways to use it as in a fortified scenario. For example, on your front line you have it set up where as the enemy unit comes in it will take 3 shots from your ranged units. So you set up the first two on the left with accuracy, and the 3rd on the right with barrage. And then just get in the habit of going left to right with your ranged attacks. This allows you to use the promotion without thought.
Do note that depending on how sturdy the units are, you may need to do a 2 accuracy to 1 barrage or 3 accuracy to 1 barrage set up. If your accuracy units are doing ~30ish damage, you can use the first scenario, if your down in the 20s best to use a 3 to 1.
Cover
I use cover sparingly for ranged units, as your goal is to get them highly promoted into those force multiplying promotions.
If your near city areas, and the city is strong enough, you may need cover to survive some of the bombardment. Or if you find yourself in archery duel commonly, technically a cover archer is a little bit better than an accuracy one (though its not a big difference).
So cover is more a promotion you "have" to use to survive the current conditions, instead of one you want to use.
Logistics
Similar to range, this is your major force multiplier, and so should be your default Tier IV promotion. It also generates XP more quickly, so even if another promotion might be slightly better in a circumstance, I still normally get logistics so I can more quickly get to the other one.
Indirect Fire
Not as useful as compared to the accuracy line, as with 2 range you get blocked less than with 3. Also with the -30% from logistics, remember that every additional attack penalty hurts a little bit more. I will often consider going Accuracy I or Infiltrators unless I am really in a scenario where I need to remove the blocks.
Infiltrators
This is a weird promotion but properly used gives a very large bonus. Honestly the -15% for being near another unit I would ignore, if you can get your unit alone than great but the penalty is not that big compared to the rest of the promotion and I would never hurt my line formations for the bonus.
So this promotion is used for ranged units that you are pushing into enemy territory, as opposed to your defender units that bombard enemies coming into your borders. As long as you make sure its the 2nd ranged unit to attack, you are looking at a full +35% attack bonus even with that -15%.....the best boost you can get.
I don't get this promotion a lot, and of course only after indirect fire, but the combination of this promotion + logistics can really murder units.
Mounted Melee / Armored
Drill Line
Spoiler :
In general, mounted units are not great city takers and tend to be more "offensive" than standard infantry. So drill tends to be a weaker promotion line for them.
That said, some horse UUs like Songhai's Mandekulu or Byzantium's Cataphract are much better city takers than normal, and so can be equipped with drill for quick city assaults.
In this cases, the horse is best served by attacking the city and pulling back, which reduces the ranged fire they take and grants them increased longevity.
Now once the armored units come into play, drill also increases in strength, as armored units are strong enough to still be good city takers even with their penalties.
Sentry
Vision is very important, but if I need it I generally use the scout line to provide it, as that is literally their job. As such I almost never use this promotion, if I'm spending horses on a unit, I want its promotions to be meaty.
Stalwart
Often I have these units dive in to finish a unit off, so anything that lets me survive the counterattack better is a solid gain. This is still a solid promotion.
Blitz
While blitz is not great on infantry it can be very solid with mounted units. The main reason is pillage. A mounted unit can attack a city, pillage a tile or maybe 2, and then attack again....mitigating the "double damage". This is especially true with tanks that have high movement and so can often pillage a few times.
Mobility
More speed is always useful, it lets you reach deeper with your horses, pillage more if your doing a run in enemy territory, and cross 3 rough terrain tiles before tanks. This is my default Tier IV if I'm going drill and I haven't yet gotten tanks. With tanks, I generally consider blitz more strongly.
Formation
Unless you have a UU like the winged hussar that starts with formation, I wouldn't generally pick this up. Your not going drill on a horse unit to make it better against other horses, I would rather just take shock for that normally.
Shock Line
Spoiler :
Mounted units are great flankers, able to move in to provide flanks and move out again as needed. So the shock line tends to get a lot of use for mounted melee.
Charge
Charge is my default promotion for mounted melee and I rely on it heavily. I find it often crosses the threshold between severely hurting a unit and killing it outright. As I often use mounted melee to snipe key siege or ranged units, this can be critical. And Charge II is murderous on how much extra damage it can generate.
Later game, charge combines very well with Splash Siege, as even just a 5 HP wound is enough to trigger charge.
Overrun vs Mobility vs March
As I said, Charge and Charge II are my common promotions, so I only go Shock III into these promotions very sparingly.
Ultimately I don't use mobility much in these scenarios, march and overrun are both just very good force multipliers. March is great on horses that can run in and attack, and pull back to a medic (or even better a city with a medic for some real healing). Overrun gets a lot of use as flanking is so common for horses and they tend to be offensive.
So ultimately its more preference than tactics at this point if your using these promotions.
Skirmisher
Accuracy vs Barrage
Spoiler :
Ultimately I do not think Barrage is a good promotion line for skirmishers. Logistics is weakened because skirmishers prefer to dart in and out quickly, consuming 2 movement to attack is not ideal. Accuracy is generally better than barrage on base stats, and unless you are making tons of skirmishers I think its better to make them all accuracy.
Parthian Tactics
I consider this the default skirmisher promotion. When using skirmishers, the major question is always "can I get to an open terrain spot and get out safely?". As such extra movement is hugely beneficial. And the lack of ZoC can also open up opportunities for attack you may have not had otherwise. It is rare that I do not take this promotion first.
Firing Doctrine
A solid Tier V after Parthian, I will sometimes take it first if I'm using my skirmishers defensively and I know I will be doing the same attack routine for a while and don't need the extra movement.
March
March is not a good promotion for you here. Skirmishers used properly should not be taking hits, and when they do they already take a lot of damage, the defense penalty from march could get your unit killed.
Last edited:
