Expansion refers to the initial phase of the game where players are mostly fighting independents and quickly taking unclaimed territory.

Depending on the size of the map or the efficiency of the players, it might last around 10 or 20 turns. There is no strict definition, but it might end around when the first player versus player wars start, or when the harder-to-take thrones are the only independent provinces left to claim.

Because it's easy to test in singleplayer game quickly and repeatedly, and it follows consistent and predictable patterns, it will often be a very finely tuned phase of the game when it comes to veteran players.

Expansion involves strategic tradeoffs: nations that are good there but might be comparatively weak late on will look to gain an early edge and snowball out of control, while more greedy strategies might try to make the most of it.

Players can make a number of choice to tilt that balance, such as investing in an awake pretender that can be used to help accelerate their expansion, or scales to help accelerate their initial troop production.

For more indepth information, you can checkout Naaira's expansion guide.

There are several factors that influence how many troops you will need to field to take acceptable losses while maintaining a fast expansion. On the one hand, you you want expansion parties to be as small as possible, so you can churn out more of them. On the other hand you want them so big that they take few casualties. This is a difficult balance to strike and I recommend doing 5+ test games from turn 1 to turn 12 where you get comfortable with the units of your chosen nation and their performance against different types of independents before you join a multiplayer game. The minimal goal should be 12 provinces by turn 12, but ideally you want 15-20. Several factors influence how hard expansion will be, among other things your own troops, types of enemies and your positioning.

Depending on your troops, expansion can be quite easy or very difficult. Especially none or lightly armored troops with low HP (e.g. Xibalban Zotz bats, Rlyeh Lobos Guard) take a lot of attrition and need finesse to deploy them. The heavier armor gets, the fewer losses you will take and the more provinces an expansion party can take before it needs to get reinforced. If you are a newer player, I recommend starting with MA Ulm Plate Infantry, EA Vanheim with Barskin Vanhere or Mekone Spartan Gigantes for this reason and work your way to lower protections. If you experiment with your bless avoid Charged Body like the plague, as it will kill your own units. Note that while (glamoured) cavalry is often strong against smaller forces, they can get surrounded and picked apart by larger armies as their high defense gets lowered by the many attacks and their glamour fails to take so many hits.

Super combatant pretenders [SC] are often used to increase early expansion significantly. They generally have high HP, high protection and Regeneration / Recuperation / Awe to mitigated damage and afflictions. While they are very tough, they can still fall to dangerous enemies with high damage attacks. Larger numbers of Lizard Warriors, Knights and barbarians should be avoided (see this demonstration. Titan pretenders (Dominion 3 category) often need equipment or spells before they can take on larger groups of enemies (e.g. Great Mother needs armor) which is why many players prefer monster pretenders (Dominion 2 category) with high natural protection instead for expanding. Generally, pretenders should buff themselves two or three times with only the most necessary spells or just hold three times in the back and “Attack Closest” to not build up too much fatigue and avoid crits. Dragons are special as most can fly and they have a breath attack. While it can be tempting to hold two times and attack the rear to kill enemy commanders, if they fail to kill the commanders fast enough they can get bogged down and surrounded. Specifically enemy nature mages can be dangerous to them with Vine Arrows which entangle pretenders and make them easier to kill for enemy troops. Generally, it is easiest to let Dragons hold twice in the far back & “Fire Closest”, so they can use their deadly breath attack once or twice to thin enemy ranks.

Another major factor are the troops you are facing. They fall into two categories: normal and difficult. Let's start with the normal foes:

• Standard independents: These forces number around 20-40 and consist of mostly light infantry, short-bowmen and some heavy infantry. Tribe Warriors (expect Bone Tribe) also fall in this category, they commonly field half melee and half ranged fighters. Wolf Tribe Warriors can be more dangerous to light and medium infantry due to wielding two weapons. By positioning your forces as far back as possible on “Hold & Attack Closest” and buff / bless your units, you can often rout or weaken the faster light infantry out of position and go on to fight the slower heavy infantry afterwards. The bowmen will stand far back making them inaccurate.
• Large independent forces: These forces number 60-100 troops of similar unit composition described above and you will need a proportionally large force yourself.
• Undead: Sometimes you will face a province with undead. These could be ghouls, Soulless and Longdead, but also Longdead Horsemen. As they often appear in large numbers, you should bring more troops to hold a line. With your Prophet on hand, you can easily banish (script 5x Banish or your Custom Priest spell equivalent) huge chunks of the undead and win with few losses. Against Longdead Horsemen 5-10 chaff units to take their lance charge in front of your troops can stall until the prophet kills them.

The above were the easy cases, now lets take a look at common difficult enemies. These enemy types will need more troops and / or specific counters to beat them. If you don't have the proper responses to these threats you should avoid them until later and take easier provinces instead. If you have assassins, they can take care of the commanders and you can rout leaderless independent forces without a difficult fight, though Mounted Commanders / Troglodyte will be difficult to assassinate. Finding the right balance of troops you bring against these is a matter of practice and depends on what your nation can field.

• Hard-hitting light infantry: These can for example be Barbarians, Cavemen, Bone Tribe, Lizard Warriors or Cynocephalian Warriors. They do very high damage and some have piercing weapons as well as multiple attacks. They can kill even pretenders with high protection (~25) and will cause severe causalities to unprepared armies. In addition, Lizard Shamans can curse your expanding god, cripple him for the rest of the game, and Cynocephalians fight in caves where your troops get a severe skill penalty (-3 AS, DS, prec) if they don't have Dark Vision. Your best bet is to use ranged attacks (archers, even slingers, ranged mercenaries) against the low armored shield-less infantry and mop them up with spear & shield infantry. You can also effectively use javelins, but you'll need them in decent numbers (~30) to make effective volleys.
• Horse Tribe Cavalry: These mounted archers can be difficult to fight against without the right tools and also have a piercing lance attack. Shields, especially Tower Shields, as well as armor help reduce the arrow damage significantly. Roman troops with Tower Shield and javelins hold up quite well under fire and can throw two salvos of javelins into the vulnerable horse archers. Other troops and pretenders can “Attack Rear” from the top or bottom of the battle field to roll up the formation from on side. As you want to reduce the time under fire, troops should in this case start at the front, though pretenders can still buff up in the back and then attack a flank, as they can shrug of arrows.
• Heavy Cavalry: Heavy Cavalry, Cataphracts, Knights and Jade Amazons pose three problems: they have powerful piercing lance charges, high defense and medium to high armor. The lance charges can be problematic for expansion that relies on high protection like pretenders or Plate Infantry (see demonstration video above). It is best to recruit expendable troops (also called chaff) and use them as bait to take the lance charges. Now that you have pulled their teeth, the cavalry only has mediocre Sword and Hoof attacks. As mounted units have high defense, your troops are less likely to hit. To Counter this you can either surround them with numbers to harass their defense down so they can be hit, bring high attack skill troops, capture them in nets (e.g. Retiarius, Mermen, Ichtyid) or ground them with magic (e.g. False Fetters, Earth Meld). A few fire elementals (Conj3) can also be very effective, soaking lances with their ethereal bodies and dealing fire damage against the short weapons & hoofs. Lastly, you'll need to punch through their protection with high damage or (armor) piercing attacks. All in all, while a handful of Heavy Cavalry can be dangerous, a charge of 20-30 can be very deadly early on and has to be prepared for.
• Elephants & Troglodytes: Early in the game, these two are quite dangerous due to their trample attack that deals 16-20 armor piercing (!) damage, if the unit can't evade. This is especially dangerous to tightly packed formations (Vaetti, formation fighters) and units that rely on glamour. The latter suffer because even if the trample misses, they will still take 1 damage and dispel glamour, making them easier prey. While one or two elephants can often be dealt with by drawing the speedy animals into your forces and killing or routing them as fast as possible, you'll need to counter larger numbers. As trample works only against smaller units, bringing same size troops (size 4-6 giants, size 6 pretenders) with you will stop the trampling and you can then take advantage of their mediocre attack skills and low attack density to cut them down easily. If you don't have that option, you can mass ranged attacks against their low protection or bring magic against the low moral (elephants) and magic resistance. Spells that help are False Fetters (Alt2) / Bonds of Fire / Sleep / Prison of Fire / Paralyze / Charm Animal (Thau2-5) to ensnare / stun / enslave, Body Ethereal (Alt4) to negate their trampling damage and Panic / Terror (Thau3-4) to rout them.

As the reports on enemy troops in a province are quite vague and can display from 50% up to 200% of the actual force each turn, you should watch their numbers over several turns to get a good estimate. The more numerous a unit type is the earlier it will be named in the report (i.e. [Militia, Archers, Heavy Infantry] will likely have a lot of Milita). For dangerous provinces and especially thrones, you can use scouts to attack and immediately retreat (called pinging) the province to get an accurate report on enemy numbers. As you should recruit lots of scouts in conquered provinces outside your forts anyways, this trick can help reduce your losses.

Oftentimes expansion can fail not because your troops lost, but because the commander was killed and the troops routed. This can have many causes:

• If the commander was scripted to “Stay Behind” but runs suicidally at the enemy and throws javelins at them, you can script “Hold” two or three times so he actually waits.
• If he has low armor and often dies to arrows (e.g. priests), there are several ways you can improve his chances. First, you can assign him up to five bodyguards and they will try to stay in his square and catch arrows (hopefully with shields). For human sized units with three troops per square, this will reduce the chance that the commander gets hit to 33%. Another possibility is to set him as far back as possible on 5x “Hold” and set the troops in line formation several paces in front of him on “Hold & Attack” with a space between them. When archers now walk up and start shooting, fewer arrows meant for the troops will hit the commander.
• Flanking enemies can also often be the death of a commander. If there aren't any dedicated flanker like cavalry, you can often let enemy troops converge on your front by staying in the back with on “Hold & Attack Closest”. If you expect cavalry flanking, you can bring an extra squad of chaff, position it on the top or bottom of the battle field across from the cavalry and set them to “Hold & Attack Cavalry” to intercept them.
• Against flying enemies it is best to put your troops in square, not line, formation and put the commander in (nnot outside) the front end of the square on 3x Hold as fliers will generally land in the rear.

There are several considerations when planning the route you want to take your forces on. Generally, you want to get to strategic choke points and rich farmlands before your neighbors and fortify them with castles as soon as possible. Another valuable resource to get are good independent mages like Crystal Amazons, Shamans and Garnet Sorceress. These can be so important as to start a war over them and should be secured as soon as possible. You also want to cut off enemy access to independent provinces as much as possible so that opponents can't take them and you have time later on to conquer cut off provinces without interference. Another consideration is taking over the provinces next to your capital, especially resource heavy forests and mountains. This unlocks more resources to recruit additional armored troops in your capital and will allow you to churn out more expansion parties. This is very important for nations that rely heavily on resources for their troops like MA Ulm and EA Mekone.

If you want to test out and tune your response to specific encounters, I suggest creating a test game on a map with two human players. Once you scripted your expansion party against independent forces, you can “Save game and quit” then go to the save file location (Main Menu > Tools & Manuals > Open User Data Directory) and go to the folder “savedgames”. There you can make a copy of your game and then load the game and let the battle play out. If you want to test different positioning, army composition and spells you can reload the save by deleting the save file, making a copy of your backup and renaming it (without “* - Copy”). This way you can find the best approach to defeat certain independents faster then doing repeated expansion test.

• Dominions 5 - Guide to Expansion (by Shinuyama)
• Dominions 5: Dominions 5 Quickstart Tutorial (by Attica, expansion tips at around ~30 minutes in, but I recommend watching the whole video)
• Dominions 5: Early expansion (by GeneralConfusion)
• Dominions 5: Commentary on expansion (by Lucid and Saquenay)

Original post: Dominions 5: All Nations Guide