Act I has 11 Turns.
No matter which of the randomized paths the player chooses, there is always a limited amount of options the player can encounter at a certain turn number:


There are two different unit pools for the regular battles up to the first armory in turn 4 and for the regular encounters in the second part of the act.
During turn 1 to 3, the player can encounter 4 different armies:
Roaming Brigands
Shambling Host
Goblin Raiders
Orc Scouts
Each army can come up more than once in a campaign, but not in subsequent turns.

The players' army will have the 3-5 starting units:
The commander with his retinue plus two additional options which can might come in pairs in some cases.
These starting armies would usually have the equivalent of 200 to 300 points in custom battles.
At challenge level 2 or higher, the regular battles in this phase have 2 or 3 units with the equivalent of 170 to 204 points.




Strength and weaknesses:

[spolier] [/spoiler]

The Roaming Brigands have 2 unit slots, which always feature the same units.



Tipps and Tricks:
Use your higher unit count and mobility:
Human armies often feature a large infantry corps which is supported by smaller fast attack and ranged support elements.

The Archer unit of the Roaming Brigands will stay behind and shoot at the nearest visible target, while the swords will push forward slowly towards their nearest target.
The unit which is tasked to neutralize the archers should move into charge range after the archers have activated. This way it can take advantage of the fact that the charge phase preceeds the strategic phase in the game loop where shooting attacks take place.

To avoid as much damage as possible, the player can present a target in cover and in long range with Defence 4 or higher to the Archers and charge the isolated swordsmen with multiple units from the flanks or rear. Artillery units like Bolt Throwers are ideal to catch low powered ranged attacks. They are more difficult to hit due to their „Protected Crew“ special rule, do not loose damage output when they loose wounds and automatically recover a wound after every battle, no matter whether they have lost any wounds during that last battle or earlier. Unless they are willingly exposed to ranged attacks, the number of their wounds at the start of a battle is rarely relevant. They will not hold their ground in brawls anyway.

The Shambling Host has three units and up to 200 points.

Two slots have a 50% chance to be filled with a unit of 15 zombies, and an equaly high chance to be filled with 15 skeleton warriors.
The Skeletons have a charge bonus of power +1 in the turn of a charge due to their handweapons and the same defence as the Zombies due to their shields. This bonus will usually not make any difference though.



Tipps and Tricks:
Divide your opponent:
Undead Nations often have a mix of very fast and very slow units, which makes it particularly easy to divide their armies.

The fast but squishy Dire Wolves of the Shambling Host will push forward and can often charge into the players deployment zone in Turn 2. Any wounds they loose by ranged attacks have a massive impact on their damage potential. They will charge the nearest visible unit in range that is presented to them. This charge can often be delayed by moving out of their range once they moved or by fleeing with a unit with high discipline. Such a feint retreat requires an assisting unit that is able to intercept an subsequent rear charge of the bait unit, ideally with a flank charge against the wolves.

The two undead infantry units are vulnerable to skirmishers as well. They cannot be routed, so melee focussed armies should charge each of the slow infantry units with 2 units simulatiously to avoid damage in prolonged engagements. It is very unlikely that these units survive a second turn of combat against more than one opponent with skill 3 or higher. Even units without upgrades typically remove 20% to 30% of their 15 models per turn on average. In addition they loose 1 to 3 models per turn when they loose a turn of combat.

Goblin Raiders have three activations and can have the most variety.
The units have the equivalent of 192 to 204 points in custom battles.
There can be not only different flavour of infantry units, but either no or one ranged support unit
and between zero and two fast attack units.



Tipps and Tricks:
Rout your opponent:
Goblin-focussed Greenskin armies often have a lot of models and wounds, which makes skirmishing less efficient than against other armies. Their low discipline in combination with mediocre defence and damage output makes it easier to win a combat and make a unit of goblins run though.

Goblin Raiders are the only opponent in that early phase which can vary in its abilites. Two of the three unit slots can feature either a fast attack unit or an infantry unit – one of which can be a ranged support. That can make the army offensive, defensive or an allrounder. The deployment should take all options into account.

The player will often not have more units than the AI, which can make it more difficult to outmaneuver and kite this army.

Match up the right opponents:
The Goblin Archers have Defence 2, while all other goblin units have Defence 3 due to their shields.
This does not make a difference when they fight an opponent with Power 4, but is very relevant when they are hit with Power 3 or 5.

Power

# of attacks with skill 3 to deal 12 wounds vs defence 2

# of attacks with skill 3 to deal 12 wounds vs defence 3

Skill 3Power 3

36

48 (33% tougher than defence 2)

Skill 3 Power 4

36

36

Skill 3 Power 5

29

36 (24% tougher than defence 2)

Orc Scouts have 2 activations with 200 points which will always be a unit of Boar riders and a unit of Orc Warriors.


Divide your opponent:
Orc based Greenskin armies often have a mix of units with different speed, which makes it easy to divide their armies and isolate single units. Their discipline is only slightly higher than those of Goblins, but their higher defence and power makes it more difficult to win a combat decisivly enough to rout a unit. Outmaneuvering these more expensive units for charges into their flank and/or rear to avoid their attacks is even more rewarding.

The Boar Riders are the primary target for ranged attacks. Their higher defence of 5 is irrelevant versus Power 3, which is most common for ranged weapons. They also loose damage output beginning with the first model they loose.

The Orc Scouts have the toughest and stongest units in this early phase. Both units of the army can in theory tank almost as many low-powered attacks than the entire Shambling Host, provided the Orcs do not run away. Kiting or simultanious attacks of multiple units against flanks and rear of an isolated orc unit are both viable options to avoid damage.
Combining multiple units against one is also crucial to avoid that the orcs change their facing after the first turn of combat and bring their strong frontal attacks to bear.