The floors where Act 1 runs actually die
Most Act 1 deaths in Slay the Spire 2 happen in two places: the first elite you fight with a mostly starter deck, and the boss floor you reach with under 30 HP. Everything between those two points is survivable if you know what each fight is asking of you, and in this game every enemy intent is telegraphed, so the information is always on screen. The problem is rarely surprise damage. It is arriving at a fight whose specific check your deck has not built an answer for yet.
First, the structure. Act 1 is not one map. At the start of the act the game rolls one of two variants, and each has a completely different pool of normal enemies, three elites, three bosses and its own event list. Overgrowth (Act 1a) gives you the ruins-and-vines theme with Nibbit and Mawler as normals, Bygone Effigy, Byrdonis and Phrog Parasite as elites, and Vantom, The Kin or Ceremonial Beast as the boss. Underdocks (Act 1b) is the sewer-dock variant with Fossil Stalker and Haunted Ship as normals, Skulking Colony, Terror Eel and Phantasmal Gardener as elites, and Waterfall Giant, Soul Fysh or Lagavulin Matriarch at the top. You cannot target a specific boss, so your deck has to be generically ready, not tuned for one fight.
Second, the numbers, which define what your deck must be able to do by each stage. Normal enemies sit between 42 and 72 HP and swing for roughly 10 to 14 on their damage turns. Elites range from 61 to a punishing 140. Bosses run from 173 up to 252. Translated into deck terms: by the first elite you want to be killing about 25 to 30 HP per turn while still blocking, and by the boss you want enough front-loaded damage to close a 200-plus HP fight before its loop buries you.
Third, the failure pattern. Players who dodge every elite arrive at the boss with a thin deck and no relics, and players who fight elites back to back with no rest site between them bleed out halfway. Our beginner FAQ answer is deliberately not a fixed formula: fight an elite once you have one or two real answers in the deck and a campfire reasonably close before or after it. Elites drop relics that can define the entire run, so total avoidance is its own death sentence.
One version note before the details: everything below reflects v0.111 beta, the current Early Access build as of this update, and all names, HP values and mechanics come from our verified game database. Where a number is single-source or in flux, we say so explicitly rather than guessing.
Nibbit and Mawler: reading the Overgrowth normals
Nibbit is the first real pattern test in Overgrowth, a 42 to 46 HP creature running a fixed three-turn loop. Turn one is a 12-damage ram. Turn two is a 6-damage swipe that also gains Block. Turn three is a Hiss that grants it 2 Strength, and then the loop repeats with every damage number now hitting harder. The fight is a countdown: each cycle that passes makes the ram turn more expensive to survive, so slow decks lose a war they were winning on turn two.
The correct play is to focus one Nibbit completely dead before touching the second, because pairs stagger their loops. If both start their loops offset by a turn, you face alternating 12-damage turns instead of one big synchronized spike, but if both sit on Hiss turns you watch two Strength counters climb at once. Kill order beats split damage here. Save your Block for the ram turn, treat the swipe turn as your free aggression turn, and only spend defense on the Hiss turn if your hand is otherwise dead.
Mawler is the other Overgrowth normal, 72 HP with a more aggressive shape. It opens with claws that hit four times for 2 each, then alternates a 14-damage Tear with more claw barrages, and roars exactly once in the fight for 3 Vulnerable. That roar turn is the whole fight. If it lands and you keep tanking claw hits afterward, every multi-hit chunk grows by 50 percent, and claws are exactly the kind of small repeated hits that punish sitting on Vulnerable.
So defend hard on the roar turn. Block the claws normally, but when the intent shows the roar, put up whatever you have and consider killing it that turn if you are close, since a dead Mawler cannot debuff anyone. Weak is excellent value in this fight specifically because the claw turns are multi-hit: Weak shaves 25 percent off every one of those four swings, which is far more total mitigation than it gives against one big attack.
Cheap tools that answer both fights: Neutralize on Silent applies Weak for zero cost on the multi-hit turns, Falling Star on Regent bundles damage with both Weak and Vulnerable, and any Artifact effect can eat the Mawler roar if you have one. Nibbit teaches loop discipline, Mawler teaches debuff respect, and both lessons are ones the Act 1 elites will retest with bigger numbers.
Fossil Stalker and Haunted Ship: the Underdocks skill check
The two Underdocks normals are less about damage racing and more about precision, and they kill players who treat normal fights as free. Fossil Stalker, 51 to 53 HP, carries 3 stacks of Suck, and the mechanic is exactly as unpleasant as it sounds: every unblocked hit grants it 3 Strength. It opens with a 12-damage bite, and once the snowball starts, every later bite lands harder than the one before it. Our database tip is blunt for a reason: block every single hit, because one leak starts a snowball.
Treat the fight as a blocked-hit discipline test rather than a race. One leak does not lose it, but two or three leaks turn a manageable skeleton into something that deletes a third of your HP bar per swing. Fossil Stalker is the cleanest argument in Act 1 for keeping a floor of Block up every single turn instead of reacting only to big intents, and it is the normal fight where Artifact-style effects and cheap Block draw genuinely earn their card slots.
Haunted Ship, 63 HP, runs a two-turn script. Turn one it rams for 10 and shoves 2 Wounds into your deck. Turn two it Haunts, applying 2 each of Weak, Vulnerable and Frail but dealing no damage at all. That second turn is a gift: it is your all-out aggression turn, a turn where zero Block is required and you should dump every attack you have, because the ship spent its turn on debuffs instead of damage.
The complications are the packages. The 2 Wounds clog future draws for the rest of the fight, and the triple debuff turn, if you cannot answer it, leaves you Weak, Vulnerable and Frail heading into the next ram. Artifact effects are the premium answer: saving one Artifact charge for the Haunt turns a curse turn into a joke. Otherwise, have any discard outlet ready to shed Wounds, or lean on exhaust synergies where Wounds actively feed you. Ironclad decks built around True Grit and Charon's Ashes genuinely do not mind the Wounds at all, since exhaust payoffs convert garbage into damage.
Together these two fights teach the Underdocks tone: the variant is not more damaging than Overgrowth on paper, but it asks for cleaner play. Block discipline beats Fossil Stalker, tempo recognition beats Haunted Ship, and both lessons carry directly into the variant's elites, which escalate each idea into a real check.
Bygone Effigy and Byrdonis: the Overgrowth elite checks
Bygone Effigy is the 127 HP elite that decides whether your deck has a plan. It cycles between asleep and awakened states, and the sleep phase is your free setup window: it is not attacking, it is handing you turns. The correct response is to spend those turns on things that compound, not on chip damage. Powers, Scaling, Star banking on Regent, Frost orbs on Defect, Poison applications on Silent, anything that makes your later turns stronger is worth more than 6 damage now.
Then the wake-up turn arrives, and that is the moment the fight actually starts. Hold Block specifically for the turn it wakes, because the transition hit is where unprepared runs take their biggest single chunk of Act 1 damage. The rhythm of the fight is set by the enemy itself: free setup, pay for it on wake, repeat. Decks that waste sleep phases attacking for small numbers arrive at the second wake-up with the same weak engine and less HP.
Byrdonis, 91 HP, is the simpler and more common Overgrowth elite check, alternating Dive and Peck turns for steady mid-range damage that pressures your HP every single turn. There is no gimmick to exploit and no phase change to play around. It is a raw question: can you output enough damage to kill 91 HP while blocking a meaningful attack every turn, for about five to six turns?
The tip our database records is to Weak its Peck turns and race it down, and that is genuinely the whole strategy. Weak on the heavier turns of the alternation stretches your effective HP, and everything else goes face. Neutralize and Falling Star are the cheap Weak sources; Weak Potion exists for decks with no in-deck answer and is well spent here rather than hoarded for the boss, since elite fights are where most real HP loss happens.
Framing both elites as deck audits: Bygone Effigy audits whether you have anything worth setting up, and punishes starter decks that can only play Strikes on curve. Byrdonis audits whether your damage and Block can coexist in the same turn cycle. If you cannot confidently pass both audits, the correct move is pathing to a campfire and a shop first, taking one more card reward fight, and returning with an actual engine. The third Overgrowth elite, Phrog Parasite, audits something different entirely, and it is the one players underestimate most.
Phrog Parasite and Phantasmal Gardener: swarm discipline
Phrog Parasite is only 61 to 64 HP, which makes it look like the friendliest Act 1 elite. It is not, because it is a two-phase fight wearing a one-phase disguise. In phase one it alternates Infect, which shoves 3 Infection statuses into your discard pile, with Lash, a 4-hit flurry for 4 damage per hit. Infection statuses are junk cards rotting your future draws, so phase one is a pressure trade: it damages your deck while Lash damages your HP bar.
The fight only ends after phase two. On death it triggers Infested, spawning 4 Wrigglers that are stunned on their first turn, and the fight continues until every one of them is dead. That stunned opening turn is your window to set up AoE or unload burst before four bodies start acting. The core planning error is spending every scrap of AoE in phase one and arriving at the spawn with only single-target attacks, then watching four Wrigglers grind you down over multiple turns.
So the discipline is: hold back. Save your AoE for the Wriggler turn, and clear Infections during phase one with any Exhaust or Transform effect you own. Whirlwind on Ironclad, Astral Pulse on Regent, Tempest-fed Lightning on Defect, Festive Popper or Mercury Hourglass if you own those relics: these are the reserved ammunition. Decks with none of those should burst the Parasite down as fast as possible to minimize Infection count instead.
Phantasmal Gardener is the Underdocks swarm elite, and it attacks the problem from the opposite direction. You face four gardeners at 26 to 31 HP each, all carrying Skittish 6, which grants them Block the first time they take damage each turn. Multi-hit attacks, the standard answer to many small bodies, get partially absorbed: your first hit feeds them Block that blunts your own follow-up hits that same turn.
The counter is single big hits, one target at a time. A card that deals 15 once beats two cards dealing 8 twice against a Skittish board. Kill order matters too: the four gardeners share a Bite, Lash, Flail and Enlarge loop running at staggered phases, so watch which one is closest to its Enlarge turn and delete that one first. Pop them one at a time with your biggest single hits and the board pressure collapses linearly; chip everything evenly and all four reach their payoff turns alive.
These two elites together teach the actual Act 1 elite skill: matching your damage shape to the fight's shape. Phrog Parasite rewards held-back AoE, Gardener punishes it. Reading which fight you are in before spending your burst is worth more than any individual card pick.
Skulking Colony and Terror Eel: damage caps and attrition
Skulking Colony, 79 HP, is the elite that hard-counters a specific and very popular deck shape: the single huge hit. It caps the damage it can take per hit, which means a 30-damage attack and a 40-damage attack both land as the same capped number. Decks built around one massive strike, most notably the Regent's Forge-empowered Sovereign Blade archetype, discover that their entire damage plan has a ceiling painted on it mid-fight.
The database answer is that multi-hit attacks and damage over time bypass the cap, because they are many separate hits rather than one hit. So Poison stacks tick for full value, Doom executes at its threshold regardless of any cap, and a 4-hit flurry pays full price on all four hits. If your deck is all single big hits, Skulking Colony is the elite to path away from, or the fight where you lean entirely on your second damage source. Silent and Necrobinder walk through this fight; a committed Forge Regent should genuinely consider a different branch on the map.
This is also the elite fight where the variant matters for planning. Underdocks also contains Terror Eel at 140 HP, one of the beefiest Act 1 elites in the game. Terror Eel has no documented gimmick in our database beyond raw staying power; its check is simply whether your deck has enough sustain to survive a long fight. That is the opposite problem from most Act 1 elites, which ask can you kill fast enough. Terror Eel asks whether you can still be blocking meaningfully on turn eight.
Practically, that means attrition resources win here. Scaling Block rather than burst Block, healing, any engine that improves each turn. Anchor-style opening Block, Frost stacking on Defect, exhaust-based defensive loops on Ironclad with Shrug It Off drawing into more copies of itself, Poison compounding on Silent. What loses to Terror Eel is the deck that front-loads everything, spends its whole hand by turn three, and then blocks 5 per turn while the eel keeps swinging.
The Underdocks elite trio (Skulking Colony, Terror Eel, Phantasmal Gardener) is collectively harsher than the Overgrowth trio because it asks three orthogonal questions: damage shape, sustain, and target discipline. Overgrowth asks setup discipline, tempo, and resource timing. Neither set is strictly harder, but if your run rolled Underdocks and your deck is a single-big-hit build, the map routing decision around Skulking Colony is one of the most consequential elite-avoidance calls in the entire act.
Vantom, The Kin and Ceremonial Beast boss loops
Vantom is the Overgrowth boss that looks unwinnable on turn one and is actually a puzzle. It opens with 9 stacks of Slippery, and while those stacks are up every hit you deal does exactly 1 damage. Each hit you land strips stacks while dealing almost nothing, and the fight only normalizes once the wall is down. The correct opener is therefore cheap multi-hit attacks, flurries that strip multiple stacks in a single turn, while you hoard every real damage card for after the wall falls.
It runs a fixed four-turn loop, and the database records two load-bearing facts. Turn three is a 25-plus damage killer swing, the biggest single hit in the variant, so full Block that turn or lose a quarter of your HP bar or more. Turn four is a self-buff turn, and that is your window: it is spending its turn on itself, not on you, so that is when you unload the burst you saved. Loop fights in StS2 are schedules, and Vantom's schedule hands you one free aggression turn per cycle.
The Kin is the target priority boss: a priest at 190 HP plus two acolytes at 58 and 59. The acolytes hit hard and scale Strength over the fight, while the priest debuffs you from the backline. The correct order is acolytes first, both of them, then the priest. Killing the damage dealers before they scale turns a race into a cleanup, and the priest alone, whatever it throws at you, is a much smaller problem than two growing acolytes. Single-target focus is mandatory; AoE spreads 20 damage across three bodies and accomplishes nothing against 300-plus total HP.
Ceremonial Beast, 252 HP, gains 2 Strength every turn, unconditionally. It is a pure DPS race with one wrinkle: below 150 HP it staggers, and then applies Ringing, a debuff that restricts you to playing 1 card per turn. The strategic depth is controlling when you cross that threshold. Push it below 150 on a turn when you have already spent your energy, because the Ringing turns that follow only allow your single best card each turn, and a hand of great cards is worth nothing when you can play one.
Practical lines: against Vantom, strip with cheap hits, block turn three, dump turn four. Against The Kin, left acolyte, right acolyte, priest, in whatever order they present lower. Against the Beast, respect the 150 line like a second boss health bar, cross it on your terms, and make every Ringing turn count with one high-impact card. All three bosses reward knowing the schedule in advance, which is exactly why intents being fully telegraphed matters so much.
Waterfall Giant, Soul Fysh and Lagavulin Matriarch
Waterfall Giant, 240 HP, is a DPS race with a bomb attached. Almost every action it takes adds 3 Steam Eruption stacks. When it hits 0 HP it does not die: it turns invulnerable, clears all its debuffs, and self-destructs on the following turn for damage equal to its stack count. The longer the fight runs, the bigger the explosion, so slow decks do not merely lose slowly here, they assemble their own execution.
Your options are concrete. First, kill it fast, because stacks are a function of turns elapsed. Second, save your best Block card and your best defensive potions for the explosion turn, and know that Weak does NOT reduce the blast; debuffing its attack stat does nothing for the self-destruct. Third, the elegant answer: if you can kill it while it sits at 0 stacks, it just dies, and our database specifically notes Doom executes as the way to do it, since a Necrobinder Doom execute at the threshold bypasses the invulnerable phase entirely. One timing note from the v0.108 patch: end-of-turn resolution order changed so Doom no longer resolves first, so verify the exact execute timing in the current build rather than assuming.
Soul Fysh, 211 HP, attacks your deck instead of your HP. It stuffs Beckon statuses into your draw pile: 1-cost cards that deal you 6 unblockable damage each if left unplayed. Every Beckon you draw is a tax, pay 1 energy or eat 6 damage that no Block in the game stops. The counter is discard and exhaust effects, cards that remove Beckons from your hand without playing them, or fast hands that simply pay the toll. It also gains Intangible on turns 4 and 5, and during Intangible turns all damage it takes is reduced to 1, so those are defense turns: do not waste attacks into them, just Block and prepare.
Lagavulin Matriarch, 222 HP, is a twist on a classic: it starts asleep, and it gets worse the longer the fight drags on. The standard line is to set up during the sleep, same as Bygone Effigy taught you. The advanced line, and one our database records explicitly, is that slow scaling decks may want to wake it early on purpose: if your engine needs six turns to come online, taking the fight to it immediately and banking those setup turns inside its sleep phase is stronger than a polite start you cannot survive later.
The Underdocks boss trio collectively tests tempo control: when to push a health bar (Giant), when to clean your deck (Fysh), and when to start the real fight (Matriarch). All three punish the same instinct, passivity, in three different ways.
Act 1 damage checks and the smoothest character openers
Boiling the whole act into benchmarks, rounded from our v0.111 database: 12 to 14 Block on demand handles every normal fight's damage turns. Around 20 Block plus steady output handles most elite swings. A kill rate of roughly 25 to 30 HP per turn closes elites in four to five turns, which is the window before their scaling hurts. For bosses, you need either a full-block answer for the single big turns (Vantom's 25-plus swing, Waterfall Giant's explosion) or enough DPS to end the fight before that turn matters. Those are the checklines. Decks below them should buy cards, not fight.
So which character opens Act 1 most comfortably? The Ironclad, and it is not close. 80 starting HP is the highest in the game, and Burning Blood heals 6 after every combat, which quietly refunds a huge share of early scrapes. His card pool also lines up with Act 1's checks: Bash applies Vulnerable so the 12-damage Nibbit ram turns into your damage too, Shrug It Off is Block plus a draw, Anger is a free 0-cost body, and Inflame plus Whirlwind gives elite-killing AoE that doubles as Wriggler cleanup. Our beginner guide recommends him first for exactly these reasons.
The Silent is the second smoothest. Neutralize is arguably the strongest starter card in the game, free damage plus Weak every fight, and Noxious Fumes turns every long elite fight into a winnable countdown. Her weakness is fragility: 70 HP and thin early Block means the Mawler roar turn and Terror Eel grind hurt more. The Regent has the strongest starter Strike in Falling Star, damage plus Weak plus Vulnerable in one card, and Astral Pulse is premiere AoE for Phrog's Wrigglers, but Stars take turns to bank and his floor is lower when the engine stumbles.
The Necrobinder has the hardest opening and the best boss answer. 66 HP is the lowest in the game and early Osty turns are clumsy, but if the run reaches the Act 1 boss with a functioning Doom stack, the Waterfall Giant 0-stack execute and general threshold pressure are exactly what the archetype wants; Defy's cheap Weak also covers the multi-hit elite turns. The Defect sits in the middle: Cold Snap is offense plus defense in one common, Glacier is real Block, and Ball Lightning carries elites, but orb decks want a few card rewards before they feel safe, so path him toward early fights before early elites.
Final routing advice for any character: take the first two or three normal fights for gold and card rewards, grab one or two real damage or Block cards, fight your first elite only with an answer in hand and a rest site not far away, and enter the boss above 40 HP with potions unspent for once. The boss loops above are schedules, and schedules are beatable with a mediocre deck and full information.