Civilization 6, like many strategy games, has a tactical rock-paper-scissors element. Spears beat horses, horses beat swords and swords beat spears. This leads to the idea that success on the battlefield requires combined arms. Have an army made up of a mix of spears, horses and swords, where your spears are facing off against your foe's horses, while your swords face off against their spears. The problem with this view is that it is to small. Units do not simply exist. They have to be built. Those factors can't be ignored just because they happened before the armies marched onto the field. As Sun Tzu said: "Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win". How Combat works in Civilization 6 When two units fight it is the absolute strength difference not relative strength difference that matters. A 20 Strength Warrior attacking a 15 Strength Archer will do as much damage as a 35 Strength Horseman attacking a 30 Strength Crossbowman. What is a Timing Attack The idea behind a timing attack is that instead of researching multiple different technologies to unlock various types of units and building an army consisting of a mix of different types of units you instead research one technology and build an army predominantly made up of that specific type of unit. For example, by rushing for Chivalry and building Knights you can have a stronger army faster than an opponent who tries to get Crossbows, Pikemen and Knights. Your Knight may struggle to deal with the Pikemen but you'll have multiple Knights by the time they can field a single Pikeman and you will be able to overwhelm it. What makes timing attacks more efficient than combined arms is the technology tree. It requires less Science to unlock a specific unit. Once that unit is available, building anything but it is often less efficient. In Civilization 6 it is more important for your unit to be an era ahead of its opponent than for your unit to counter its opponent. A Knight does better against a Spearman than a Swordsman. Once you have a force of Knights you want to launch your attack. You will have an advantage that will last until your target can catch up on technology and build a few units. It is your upmost objective to do as much damage and take as many cities as possible as quick as you can. Once your opponent has caught up and your advantage is gone consider making peace, consolidating your gains and preparing for the next timing attack. What is an Upgrade-based Timing Attack You can accelerate the start of certain timing attacks by using unit upgrades. Rather than building a bunch of Knights after researching Chivalry you can instead build some Chariots while you wait to finish researching Chivalry. Once Chivalry completes you upgrade all the Chariots to Knights. This requires stockpiling some Gold but it allows you to start your timing attack much sooner than before. Since the early turns are when you have the largest advantage upgrade based timing attacks are much stronger than normal timing attacks. Certain unique units, like the Samurai and Berserker, can't be upgraded into. This makes them less useful as you can't do upgrade based timing attacks with them. While upgrade based timing attacks require more advanced planning they are much more effective and what you should use as your main attack opportunities. Timing Attacks Time to move from theory to practice. What are some of the good timing attacks available in Civilization 6? Starting from the early game and working forward these are your best options: Early Game: Slingers->Archers It only requires 30 Gold (on standard speed) to upgrade a Slinger into an Archer. Archers can struggle to take cities, especially once walls are online, so this is more useful as a defensive timing. If you need to protect yourself from barbarians or an early attack Archers are hands down the best unit to rely on. Horsemen With 4 movement and 35 Strength Horsemen are effective at surrounding and overtaking enemy units, even when rough terrain is in the way. When combined with the production policy they are relatively cheap to build. This timing relies on having two copies of horses to pull off as building encampments in all your cities is often too disruptive to incorporate into early development. Warriors->Swordsman With the same strength as Horsemen Swordsman don't have as much going for them. Their slower movement makes it harder to quickly finish off ranged or retreating units. Upgrading only requires one source of Iron so once you get Iron Working you'll be able to look around and determine if this timing attack is something you can pursue. Its main advantage is speed, as the Warriors can be pre-built and potential have some experience accumulated from fighting barbarians. Chariots->Knights This is the strongest early game timing attack. The technology can be reached very quickly and the chariots can be pre-built. Keeping the momentum after the initial upgrade can be tricky as the bonus production policy for Knights isn't available until Monarchy. Mid Game: Horsemen->Cavalry This timing attack requires a long term commitment but is very strong. In order to make it work you need to beeline the bottom of the technology tree. This often means delaying naval and factory rushes. Horsemen become ineffective on the battlefield long before Cavalry become available so most of the Horsemen will be built as part of an earlier Horseman based timing attack. The survivors from this push will often become garrison fodder for Retainers (+1 Amenity in cities with a garrison) that sit idle until it is time to upgrade them to Cavalry. By this stage of the game you will have the policy that reduces unit upgrade costs. Running that policy for a turn or two while you upgrade everything will greatly reduce the amount of Gold you need to stockpile to do upgrade based timing attacks at this stage of the game. Bombards->Artillery This technology path is relatively easy to pursue. The Bombards can be built while researching the two technologies to get Field Cannons and Artillery. Field Cannons are actually an upgrade for Crossbowmen, which is why they are not part of this timing attack. While Artillery will be effective at dealing with cities it will struggle to kill units. Making this timing attack less effective than Cavalry based attacks. Late Game: Knights->Tanks If you are looking to do a late game attack this is your strongest option. It even has a second wind when Modern Tanks are unlocked. Tanks have the same combat power as Helicopters but are earlier in the technology tree. Getting the Oil to upgrade the Tanks is the tricky part. There is a good chance you will not have access to land based Oil when you research Combustion. That will delay the start of your attack until you can hard tech Plastics to access water based Oil. A foundation for war Each of these timing attacks are an opportunity you can choose to pursue. Successful domination does not require doing all of them. Rather it requires focusing on the possibilities your empire can best support and vigorously executing them. Some of these timing attacks, like those based on Swordsman or Knights, require certain resources to be present. Others, like the Cavalry or Tank, require focusing on one part of the technology web at the expense of others. A successful timing attack requires planning and foresight. Sacrifices you make preparing for the war will provide decisive advantages once the first shots are fired. Follow the advice of Sun Tzu, win first and then go to war.