[vanilla] Amphibious Invasions

[SemperFi2382]

Amphibious Invasions
From the halls of Montezuma, to the shores of Tripoli.

Introduction
Whether it is Troy, Normandy, or the Pacific Campaign that is the first things that comes to your mind, Amphibious Invasions have occurred throughout history. Now Amphibious Invasions apply to more than just an island hopping campaign, or a massive beach landing. These kinds of assaults apply to crossing rivers or small channels of water.

No matter what type of map you are on, sooner or later, either out of necessity or as a strategic option, you are going to have to land on hostile shores. This guide is setup to help you not only prepare for an Amphibious Invasion, but also to prepare to defend against one.

Before we dive right in, I am going to assume you know the basics of the combat mechanics in Civ5. If you do not, I would highly recommend that you get familiar with the mechanics first before you dive into this guide. Play the tutorials that came with the game, or check out any of the other outstanding guides found in the War Academy. The main three I would recommend are, The Mechanics of Combat, Understanding the Zone of Control, and Ranged Combat.

• Key Concepts
• Preparation for D-Day
• D-Day
• The Coastal Fortress
• Alternative Options
• Specific Civilization Strategies
• Conclusion

Key Concepts

• 1UPT = One unit per tile.
• Direct Assault = Attacking directly from the sea.
• Indirect Assault = Disembarking first, then attacking.
• Ocean = Sea (and vice versa)
• Coast = Any portion of your territory on the sea, NOT the terrain type.
• Preparation is key!
• Location, location, location!

Preparation for D-Day

You are going to need a couple of things before we start hitting the shores. For starters, some basic technology is in order. Namely, you are going to need Optics which will allow for the embarkation of your units. Unlike previous Civilization games, you do not need transports. On the plus side, this means you can build more combat units instead of having to build a large number of transports.

Civilization 5 allows only one unit per tile (1UPT), which means that preparing for an invasion is going to get rather crowded. If you are already at war, or have a large barbarian population close by, then your units should stay on the shores. Your units cannot defend themselves while embarked, which will make them easy pickings. There are two exceptions that are addressed in the Specific Civilization Strategies section.

You may find it useful to grab the Amphibious Promotion if you have the option, as it will negate the penalties for attacking from the sea and over rivers. However, if you are only attacking one or two cities from the sea or across rivers, then the Amphibious Promotion won't be as useful as a terrain bonus or cover.

At the same time as building your invasion force, you are going to need to build a couple of naval combat vessels as well. Depending on your opponents navy, you might want 2-3 or as many as 4-6. Your fleet should have a mix of targeting promotion based ships and bombardment promotion based ships. The exact ratio of anti-naval ships vs bombardment support will depend on your targets current fleet. Do not mix and match on the same unit however. Pick a track and stick with that one track!

The reason for the mixed fleet is that, for any amphibious invasions, you will need to first remove the targets fleet and then shift to bombardment support. Since embarked units are easily removed by a ship 'running it over', ensuring the target has no fleet before bringing your embarked units over is a good tactic. Early on your options are limited, but that is for another topic, which is discussed *here* (add link for Naval Combat Guide when completed)

Once Flight, and later Radar, have been researched, Amphibious Invasions take on a new dimension. As the invader, you can bring carriers with fighters and bombers to help with the bombardment phase and/or protect your embarked units. As the defender, your fighters and bombers instantly kill any embarked unit. So control of the Air will become just as important as controlling the waters around your embarked units or city.

Once you are ready, make sure your entire force is embarked before you set off. You lose the rest of your movement points once you embark, so failing to embark can cost you precious time!

Summary

1. Research Optics (to allow embarkation).
2. Build your invading army.
3. Use beneficial promotions if available.
4. Build an appropriate navy for escort and shore bombardment.
5. Embark the entire invasion force.

D-Day
Now that your units are embarked, off we go! At this point you might be asking yourself, "to where?" The obvious answer is towards your enemy! If you are at war, then you will want to take your warships to screen ahead and to the flanks of your embarked units. Since most civilizations embarked units (Songhai units and Spanish Conquistadors prevent this) can be killed by a ship 'running it over' (entering the same tile) you never want to allow an enemy ship to get close to your embarked units. As well, there is no naval Zone of Control, so enemy naval units can go right past yours. Finally, you'll need the space to allow your embarked units to be within striking distance of the coast.

Once you are on the way to the target, you will need to choose a suitable landing position. You should be preferring an area where you can land at least 1/2 your army in the first wave. Melee units need to land closer to the enemy units or city, while ranged units can land in a second wave, or behind melee units if the terrain allows.

Once the attack commences, you are going to want to use naval bombardment in a specific order. First, sink any of the enemies ships lingering around the landing zone. Second, blast anyone on the shore, focusing on ranged units first. If no more higher priority targets remain, shell the cities you are going to attack.

Try to land your forces in tight clusters. Flanking bonuses will help your units survive the first turn, as they won't be able to continue attacking on the turn they land. (Danish units can move after landing) Additionally, a Great General is worth bringing, and they do not need to land on the shore to give out bonuses. So if you have more than one battle zone when you land, you can shift your Great General around on the sea tiles to help your units.

If the target has units in the landing zone, use your navy to soften them up before trying to land. (or just land beside them and clear them on the next turn) Without the amphibious assault promotion, attacking from the sea is generally considered a bad plan unless you will kill the unit outright.

While you are bombarding the shore with your naval units, set up your invasion forces in a formation that mimics what that which you will use on land. Melee and hard hitters first, then the ranged units, including any siege units. The reason for this is that with only 1UPT you are going to have to hit the shores in waves and you do not want to be shuffling units mid-landing.

One particular pitfall to beware of is amphibious assaults against Japanese units. They will still deal maximum damage to your units even if wounded, and you will have a -50% combat strength penalty, without the amphibious assault promotion, meaning that you will take a great amount of damage just getting on to the shore, even against a one hit point unit.

If you are planning on landing close to an enemy city, ensure your navy is taking up every coastal tile touching the city. If you do not, the enemy will be able to continue building ships, which can then move out and kill your embarked units.

Summary

1. Scout ahead and to the flanks.
2. Choose a suitable landing zone.
3. Shore preparation.
4. Formation preparation.
5. Hit the Beaches!

The Coastal Fortress
Sooner or later, you are going to need to deal with the situation of hostile units landing on your shores. This section is setup to specifically address this situation.

Your first layer of defenses and biggest asset in the defending your shores from invaders is going to be naval reconnaissance. If you see it coming, you are going to have a lot more time to adequately prepare and ultimately interdict the enemy force. So, if you suspect an Amphibious Invasion the first thing you are going to need to do is have a respectable navy.

Depending on what era you are in, your choices for naval units might be slim. However, even a handful of Triremes are going to be better than not having any combat capable vessels. On a smaller maps, 2-4 naval units for defense are fine, but expect on a huge map to need significantly more. However, if you only have a small coast, you can do with less.

A rule of thumb is that you should be able to have 3-4 ships able to reach any part of your shore within two turns. So the larger the shoreline, the more ships you will need to defend it. You should have a minimum of two ships near every coastal city at all times, when you are at war. These ships help maintain the trade routes and can quickly dispatch any ship that wants to pillage your sea resources. All defensively focused ships should have the targeting promotion line, as this will help you kill off invading ships much faster.

With a respectable navy afloat, you will want to do recon on any and all approaches from the sea. That means hugging the coast, or straight across the oceans. This is why you want enough ships to be able to watch your whole coast so that every turn you will be able to see all of your land beyond the vision afforded by your borders.

Once you have spotted an invasion fleet, ensure to engage them out at sea with your ships, unless their fleet is larger than yours. If you focus your fire and kill at least one ship per turn, you can very quickly decimate your opponent's invasion forces after the naval battle. If that is not possible, or their fleet is larger than yours, you may need to fall back to the shoreline to let your city and ranged units help dispatch enemy ships.

One caveat to this approach is that you should prevent enemy embarked units from getting within landing range of the coast. With a sufficient navy, this should be fairly easy, but if you have only a few ships, it may be best to set up a 'picket line' in front of the coast with your ships, to prevent the enemy from landing. If you can get ranged land units to the shoreline, you can then use bombardment attacks to kill the embarked units.

As well, if you have an Air force available, use them to pick off the enemies embarked units. Air units instantly kill embarked units. Do watch out for enemy carriers though. If you spot one, kill it as fast as you can since they will be carrying fighter, bombers, or worse - an Atomic Bomb!

Basically, as long as the enemy has an invasion force, your navy should fight to the last man. Once the invasion moves to the land, use your navy to kill stragglers and prevent reinforcements.

Unfortunately, they might make it to your shores. Even if they prepared the landing zone, you should still be at a strong advantage. Should the enemy make it to your second layer of defenses, it is time to use your ranged units to pound them on their approach. You might only get one or two barrages off before they land, so be sure to not get stuck on the shore. If they are going straight for a city, focus on the biggest threats first, and focus your fire!

Once it looks all clear, check for other approaches, a second wave and prepare an invasion of your own. Assuming they are not crying for peace!


Summary

1. Recon.
2. Interdiction.
3. Artillery Barrage.
4. Bloody Shores.
5. Cleanup

Alternative Options
This section deals primarily with the non-standard Amphibious Invasions from simply crossing a river hex to using a large lake as a surprise invasion route.

River Crossings

The most basic of Amphibious attacks is the crossing of a river. Historically speaking, rivers have always made excellent natural barriers to deter an invasion from all but the most determined attackers.

For the most part, using ranged units to clear all enemy units near the river before crossing is a very good plan. However, eventually you will need to cross the river. You will lose your turn after crossing the river, (except for scouts and American Minutemen based units) so do pay attention to where you are crossing. Try not to leave yourself flanked by enemy units, or in a marsh if you're close to the enemy.

The Amphibious Promotion will negate the penalty for attacking across a river with melee units, so having one or two units with this promotion can make river crossings less brutal.

Large Lakes, Small Seas, Etc
This scenario allows for larger amounts of embarked units, with less focus on navies. A few ships would never be a bad thing, if you share an inland sea with an enemy. Otherwise, going across the Large Lake/Inland Sea with your units can be a much more effective method of assault, than if you tried to fight your way around it. This can be a very easy way to dodge the enemies army and hit their less protected areas.

Crossing the Channel
Sometimes, you have an island or landmass separated by a thin channel of water. One strategy that is practiced upon the discovery of Radar, is to use Paratroopers to drop on the opposite side of the channel to secure positions or delay defenders while troops cross the channel.

While Paratroopers cannot attack on the same turn as their drop, they can move around and pillage tiles. This allows you to use them to 'fortify' a coastal area while the rest of your army is moving through the water. Once there, the paratroopers can move out of the way to allow your other units to land unopposed.

Using City States and Open Borders effectively
If there happens to be a City State near your landing zone, which isn't at war with you, then you can choose to land your embarked units in their territory. This can be a very nice way to get your units on to dry land before actually starting a war. (if you were not at war with the target already) Yes you will lose influence with that city state, but they complain less than an AI about your units being in their territory.

You can also choose to buy Open Borders from an AI next to your target. This, again, will allow you to safely land your units before commencing an attack. You will however have to deal with the AIs units wandering around, which can get in your way. As well, they may ask about your forces, so be sure not to accidentally declare war on them.

This strategy is also good if mixed with paying off the landing zone civ to attack the target civ. They will more than likely send their units to their death, allowing you more space to land and move your units. If you're extra lucky, the target civ will move it's units into the landing zone civ's territory, allowing you to pick them off before getting close to their cities.

Operation Overkill
One way to ensure minimal loss during an Amphibious Invasion is to clear the way with a couple of nukes. With the technology Computers and Advanced Ballistics, you could simply perform a first strike from a Nuclear Submarine with a Nuclear Missile (or two) and annihilate anything on the landing zone. This could also be done earlier on the tech tree with Flight and Nuclear Fission with a Carrier and an Atomic Bomb (or three).


Specific Civilization Perks
Listed below in alphabetical order are a couple of Civilizations that have a slight edge during an Amphibious Invasion. Note that in some cases, it is very technology dependent.

Denmark

1. Their Berserkers (Replaces Longswordsman) starts with the Amphibious Promotion.
2. All Danish units can move after landing. Their movement points at landing are based upon their embarked movement points. Danish units also have +1 embarked unit speed.

England

1. +2 Movement for Naval Units (including embarked units)
2. Ship of the Line (Replaces Frigate) can see farther, is cheaper, and slightly stronger ranged attack.

France

1. Foreign Legion (Replaces Infantry) has a combat bonus outside of friendly territory.

Japan

1. Bushido means that even if at 1HP, they are still a threat.

Songhai

1. Embarked Units can defend themselves.

Spain

1. Embarked Conquistadors can defend themselves.

Conclusion
In conclusion, an Amphibious Invasion is a lot like a land invasion, with a couple of exceptions. It takes time, additional recon, and a little extra support to take ground. However, when defending against an Amphibious Invasion, a little preparation and aggressive tactics goes a long way.


Patch version of this article: 1.0.1.383

[weregamer]

I see at least two facts that I have experienced to be false in this article.

1) There is a naval ZOC produced by combat ships. Embarked units or combat ships that move directly between hexes adjacent to hostile combat ships definitely use up all their remaining MP.

2) Archery and siege units cannot target embarked units. Only city ranged attacks and air units can. Many times either I or an AI have saved a unit caught straggling near enemy forces at the start of a war by fleeing to the ocean - at least until a warship showed up.

[w a i n y]

Originally Posted by weregamer

I see at least two facts that I have experienced to be false in this article.

1) There is a naval ZOC produced by combat ships. Embarked units or combat ships that move directly between hexes adjacent to hostile combat ships definitely use up all their remaining MP.

2) Archery and siege units cannot target embarked units. Only city ranged attacks and air units can. Many times either I or an AI have saved a unit caught straggling near enemy forces at the start of a war by fleeing to the ocean - at least until a warship showed up.

Ranged units give 4 damage to all embarked units (except if the embarked units belong to Songhai, in which case it uses their combat strengths). Not sure about #1.

[MadDjinn]

Originally Posted by weregamer

I see at least two facts that I have experienced to be false in this article.

1) There is a naval ZOC produced by combat ships. Embarked units or combat ships that move directly between hexes adjacent to hostile combat ships definitely use up all their remaining MP.

2) Archery and siege units cannot target embarked units. Only city ranged attacks and air units can. Many times either I or an AI have saved a unit caught straggling near enemy forces at the start of a war by fleeing to the ocean - at least until a warship showed up.

Originally Posted by w a i n y

Ranged units give 4 damage to all embarked units (except if the embarked units belong to Songhai, in which case it uses their combat strengths). Not sure about #1.

for point #2 - this is exactly true. Use the ranged attack option rather than a right-click and you'll be attacking embarked units.

for point #1 - I'll have to double check, but last I used naval units, there was no zone of control.

[gladoscc]

I can confirm #1, there is zone of control.

[weregamer]

I rechecked #2, and you're right - it's apparently a UI problem with right-clicking, probably related to the "run-over" mechanics for naval attacks on embarked units. My longbowmen were able to plunk Askia's embarked units even with a right-click.

[CELTICEMPIRE]

A truly wonderful article.

[bokaj]

Awesome article! Helped me a lot. Thanks!

[musicgam3]

were can i find those circle emblems youhave in your thread?
i really want to use them for a guide i am writing.
already thanks for the time!

[Camikaze]

For an example, flight is the following:
[img]http://forums.civfanatics.com/images/war_academy/civ5/techs/big/flight.png[/img]



All the images are under http://forums.civfanatics.com/images/war_academy/civ5/ followed by the appropriate ending.

[bryanw1995]

Originally Posted by MadDjinn

for point #2 - this is exactly true. Use the ranged attack option rather than a right-click and you'll be attacking embarked units.

for point #1 - I'll have to double check, but last I used naval units, there was no zone of control.

Haha, I always manually target with my ranged attack, and I can also verify that it is entirely possible and, as stated, you do a standard 4 dmg with each shot (just like attack a non-combat unit such as a worker on land). Naval units have a ZOC, but it is slightly different from earlier civ versions.

ZOC is a bit more tricky. In the past civ iterations with ZOC, you were simply blocked from moving from one tile adjacent to an enemy to another tile that was also adjacent to an enemy. Now, you can move when adjacent to an enemy combat vessel into another tile that is also adjacent to an enemy, but if that new tile is adjacent to the same enemy ship then that movement consumes the rest of your movement points. However, if you are adjacent to enemy ship "A" and you move away from "A" to a tile that is adjacent to enemy ship "B" but not adjacent to "A", you do not lose any movement points.

[JoanK]

You see? I don't have any trouble in amphibious invasion, I just wipe out the enemy's navy and send some amphibious promoted units as first wave

[sir_toast]

this article was easily readable and concise. Try linking in other threads (ZOC would be a good one) and this would be a great improvement (kinda like the Wikipedia). I would like also to thank all contributors to the war academy. For a novice this is a wonderful boon! In addition, the similar format makes these very usable

[SemperFi2382]

Originally Posted by sir_toast

this article was easily readable and concise. Try linking in other threads (ZOC would be a good one) and this would be a great improvement (kinda like the Wikipedia). I would like also to thank all contributors to the war academy. For a novice this is a wonderful boon! In addition, the similar format makes these very usable

Thanks for the feedback!

As suggested, I added in some links and cleaned up some random typos.

[NukeAJS]

To clear up the ZOC issue regarding naval units, any units moving adjacent to an enemy naval unit (whether embarked or legit naval unit) loses all their MPs.

To clarify more, this includes army units on land moving adjacent to an enemy coastal navy unit. It DOESNT include a coastal navy unit moving past an enemy coastal army unit.

When it comes to ZOC, naval units have superior priority regarding army units whether embarked or not. So, naval units can't be stopped by enemy army units, ever. That being said, naval units can stop enemy army units always (embarked or on land), but naval units can be stopped by other enemy naval units.

[Jabberwockxeno]

Late game, I find that it great strategy for taking coastal cities or even just clearing up your landing area is this:

Build 1-3 carriers, (I did 3 carriers, 2 with bombers, 1 with fighters). Depending on how naval savy your target is, you may want to build 2 destroyers or so to defend the carriers and/or your embarked land troops.

Send out the carriers ahead of your embarked land units, and bomb any defensive units and the cities over and over until your main force gets there. Ideally, by the time your units get on an adjacent tile (works even better if it's along the coast), the city should be a OHKO to take.

Having paratroopers as your main ground force helps, as once you take 1 city, you can immediately get your troops near a city that's not as close to the shore.

For upgrades, go for mainly the ones that extend the mission ranges or healing even when taking an action for aircraft, for the boats, go for more moves per turn. Take instant heal if they are in the red zone, as you'll get upgrades every other turn or so this way.

As japan, I literally stormed nearly the entire continent this way with only 1 defeated unit over only 20-30 turns.

[slobberinbear]

The article needs to be updated for Gods & Kings, methinks. In particular, naval "overrunning" is not automatic now and stacking is allowed for one naval and one embarked unit. Also, since many naval units are now "melee" and not ranged (and can assault cities directly), this needs to be addressed. Lastly, I would probably mention the overall deadliness of the city garrison attack against embarked units. Expect losses.

I do like the general strategy information.

[SemperFi2382]

Originally Posted by slobberinbear

The article needs to be updated for Gods & Kings, methinks. In particular, naval "overrunning" is not automatic now and stacking is allowed for one naval and one embarked unit. Also, since many naval units are now "melee" and not ranged (and can assault cities directly), this needs to be addressed. Lastly, I would probably mention the overall deadliness of the city garrison attack against embarked units. Expect losses.

I do like the general strategy information.

I will update this article "soon". I've been busy with work and family things, but I have been working on a draft that I plan to use reflecting the new naval mechanics.

[Slvynn]

More importantly, embarked and Naval stacking
For now you can using 2 sea tiles bordering city commence 4 attacks just from those tiles, and land could not allow that.
Means Danmark could:
Land Siege weapons and fire,
Ranged Navy attack
Land 2 Melees and attack
Melee Ships attack
2 embarked amphibious melee units attack

It could be more effective than any land siege, because there is +++ movement.

For modern Ages the approach of Naval Melee + Amphibious Land Melee on same tile is one of best to commence Naval city sieges.

[Smoo]

Do ranged attacks on a naval/embarked stack affect both units? Or just the naval one? I haven't gotten to a late game yet, but if the embarked are shielded, wouldn't an amphibious assault be super easy if you just bring, say, a battleship and a loaded carrier with a couple of embarked amphibious units stacked with them? Soften the city then take it with just one or two direct amphibious assaults. (Assume the opposing navy has already been dealt with.)