Unlike it’s predecessor, Slay the Spire 2 has multiple possible locals for its three Acts. These locals offer up new events, enemies, and even bosses, randomly selected when a run begins.
The Underdocks are an unlockable alternative to Act 1, featuring aquatic foes, harder fights, and a boss battle against the towering Waterfall Giant. If you think you can handle it, let’s go over how to unlock the Underdocks and what to expect when you arrive.
Unlocking the Epoch

Every unlock in Slay the Spire 2 is represented by Epochs on the Timeline, moments in history from the world of Preon’s emergence, to the events of the sequel as we play it.
Epoch can be unlocked in all kinds of different ways, from reaching new Score thresholds to defeating bosses as certain characters. The Underdocks is locked behind beating each of the Undergrowth’s boss fights.
Which fight you get is random, but you’ll need to beat all three in order to access the alternate form of Act 1. This includes Vantom, the Kin, and the Ceremonial Beast.
Let’s quickly go over each to give you a basic idea on how to tackle them as you go through your initial runs.
Vantom

Vantom is a pretty standard high-damage battle, following up two light attacking turns with an absolute crushing blow on the third.
Keep an eye on the position of his tail, and get ready to defend once it starts winding back.
Ceremonial Beast

The Ceremonial Beast alternates between two effects during its phases, Plow and Ringing.
Plow is a buff the Ceremonial Beast applies to itself at the start of the fight, after which it will spend every turn charging the player and stacking strength. Lowering its HP to 150 will stun it, consuming the buff and transition the fight to phase 2.
In phase 2, the Ceremonial Beast applies Ringing every few turns, a debuff that only allows the player to play a single card for the card.
Just anticpating these effects is half the battle, with some proper blocks and decent damage, the beast doesn’t last long.
The Kin

The Kin is our multi unit encounter of the Act, consisting of two Kin Followers and the Leader behind them.
The Followers are classified as Minions, meaning they’ll flee if you can burst down the Leader, but their consistent damage and constant self buffs make that awkward if you don’t have some serious firepower.
Normally, your best bet is taking out one Follower after another before pivoting to the Leader. Be careful, once his Followers are down, the Leader will pivot to a far more aggressive pattern, so avoid as much damage as you can as you’re handling his adds.
Tackling the Underdocks

Once all three bosses are bested, you’ll unlock the Underdock, an aquatic deathtrap with plenty of nasties looking to pull you under. This is also the path to unlocking another Ancient, so keep your head on a swivel as you climb; you’re going to need it.

