Slay the Spire

One of the three Act 1 bosses (alongside The Ghost Hexaghost and The Boss the Slime Boss), picked at random each run. The Guardian shifts between Offensive and Defensive Mode - it goes defensive after you deal enough damage and grows big Sharp Hide/thorns, so stop attacking while it's in Defensive Mode (you take the damage back) and unload while it's Offensive. You'll meet it just by playing Act 1; which of the three you get is down to the run's RNG.

Kill Hexaghost, one of the three random Act 1 bosses (see also The Guardian and The Boss). Its opening Inferno scales off your current HP (it divides your HP for the hit count), so start the fight as healthy as you can and be ready to block that big second turn. Nothing tricky beyond that - reach Act 1's boss enough times and Hexaghost will come up.

Kill the Slime Boss, the third random Act 1 boss (The Guardian and The Ghost are the others). At half HP it splits into two medium slimes, which then split into smalls, so a bit of AoE or enough burst to punch it below the split threshold in one turn keeps the fight tidy. Otherwise straightforward. Down to Act 1 boss RNG which you face.

Defeat the Champ, one of the three Act 2 bosses (with The Automaton the Bronze Automaton and The Collector the Collector). At half HP he powers up hard - big Strength and Block plus a stun - so ideally burst him from around 55% to dead before he can execute that Anger/defensive turn. Which Act 2 boss you meet is RNG.

Defeat the Bronze Automaton, a random Act 2 boss (see The Champion and The Collector). It summons two Bronze Orbs and charges Hyperbeam, a massive hit that also strips your buffs - block that turn hard, and kill the orbs (or at least one) so they don't shield and beam alongside it. Reach Act 2's boss enough and it'll come up.

Defeat the Collector, the third Act 2 boss (The Champion and The Automaton are the others). It summons Torch Heads and buffs itself and them, so AoE or killing the adds quickly makes this much smoother, and watch the big turn where it stacks Strength on everything. Act 2 boss RNG decides when you meet it.

Unlock Ascension mode. Just beat the Spire (a normal Act 3 win) once with any character and Ascension unlocks for that character - reaching the true ending isn't required. This is the gateway to Ascend 10 and Ascend 20, so it's the first tick of the long climb.

Finish any combat sitting on exactly 1 HP. It happens by accident on a close fight eventually, but you can force it: let yourself get whittled to 1 HP, then win the turn without taking any more damage - block everything, or pick a turn where the enemy's move doesn't actually hit you (a buff/debuff turn). Easiest to set up against a weak, predictable enemy.

Kill three enemies in one fight with Poison (the poison tick has to land the killing blow on each). Silent, obviously - grab Noxious Fumes so every enemy is stacking Poison, then just let the ticks finish them off rather than attacking them down yourself. Any three-enemy encounter works; the Act 1 packs of three (Louses, Cultists) are perfect. Comes on the way to a Poison win.

Hold 9 Energy at once in a single turn (you don't have to spend it). Stack energy sources: base 3, plus any energy-boosting boss relics (each adds +1 per turn), plus energy cards - Ironclad's Bloodletting (+2 for 3 HP), Silent's Adrenaline (+1 and draw), or Defect's Double Energy which doubles your current energy. A run with a couple of energy relics and one or two of those cards hits 9 on a set-up turn easily.

Exhaust 20 cards in one fight. Ironclad is the natural fit - Corruption (Skills cost 0 and exhaust) plus a way to keep drawing and replaying Skills, or a Dark Embrace/Feel No Pain exhaust engine that pays you for it. Any long fight where you're churning exhaust works, so a tanky exhaust deck against a boss is the reliable setup. You'll rack up 20 without really trying once the engine is online.

Beat the Spire (kill the Act 3 boss) with the Ironclad, your starting character. He's the most forgiving class - solid block, self-sustain and brutal Strength scaling - so this is usually everyone's first win. Keep your deck lean and lean into one of two plans: a Strength deck (Demon Form + Limit Break + a big hitter like Heavy Blade), or a Barricade/Body Slam block deck. Don't be shy about skipping card rewards to stay thin. Comes naturally as you learn the game.

Kill any boss without losing a single point of HP. Note HP lost to your own cards (Bloodletting, Offering, Hemokinesis etc.) doesn't count against you - it's specifically damage taken from enemies. So either block every incoming hit for the whole fight, or burst the boss dead before it acts (see You Are Nothing). The Act 1 bosses are the easiest targets - low HP, simple patterns. A big-block or high-burst deck gets there.

Defeat Donu and Deca, the paired Act 3 boss (see The Time Eater and The Crow). Donu gives the pair Strength, Deca gives them Block and Dexterity, alternating each turn - so focus one down rather than splitting your damage (Deca first usually, to stop the block wall). AoE is great here. Act 3 boss RNG decides the matchup. If you want the Ooh Donut! achievement, this is the fight to bring a Feed to.

Defeat the Awakened One, the third Act 3 boss (The Time Eater and The Shapes are the others). It has two phases - kill it once and it revives at full HP with bonus Strength - so you need enough sustained damage for two health bars, not one big burst. It also gains Strength every time you play a Power card, so go light on Powers in this fight. Act 3 boss RNG.

Win a fight without playing a single Attack card (Skills and Powers are fine). Poison (Silent) or an orb/Power deck (Defect) does this without even trying. Simplest deliberate setup: a Silent Poison hand - Noxious Fumes plus Catalyst - and let the poison do all the killing while you only ever play Skills. Any easy encounter works.

Defeat the Time Eater, one of the three Act 3 bosses (with The Shapes Donu & Deca and The Crow the Awakened One). Every 12 cards you play it ends your turn, so it hard-counters high card-count and infinite decks - play fewer, bigger cards and don't waste plays. At half HP it heals and gains Strength, so try to burst through that threshold rather than stall. Down to Act 3 boss RNG.

Beat the Spire with the Silent. She's squishier than the Ironclad but has fantastic card draw and two strong archetypes: Poison (Noxious Fumes + Catalyst + Deadly Poison - just stack it and let it tick) or Shivs (Accuracy + Blade Dance/Cloak and Dagger). Poison is the beginner-friendly route and trivialises bosses. Whichever you build, you'll pick up Catalyst or Ninja on the way.

Beat the Spire with the Defect. Orbs are the name of the game - Frost for defence, Lightning for chip damage, and Focus (Defragment/Biased Cognition) to buff them all at once. The easy win is a Frost/Focus tank deck (Glacier, Chill, Defragment) that just out-blocks everything, or a Lightning swarm with Electrodynamics. Once your orbs snowball the Defect is arguably the strongest class in the game.

Stack 99 or more Poison on a single enemy. Silent: build Poison (Noxious Fumes, Deadly Poison, Bane) then play Catalyst - it doubles the target's current Poison, or triples it upgraded. Get a target to around 40-50 Poison and an upgraded Catalyst punts you past 99 in one card. A high-HP enemy or boss gives you the turns to stack it. You'll very likely get this naturally on the way to a Poison win / Emerald.

Reach 99 Block in a single combat. Any dedicated block card played a few times gets there - Ironclad's Barricade (block stops expiring) plus block cards stacks it fast, Defect's Frost orbs with Focus, or Watcher's block cards. Even without Barricade, a couple of big block plays in one turn - Entrench doubles your current block - will clear 99. You'll pass through this on the way to Barricaded.

Have 10 or more buffs (positive Powers) active at once in a fight. Just pile on Power cards and buff effects in one combat - Strength, Dexterity, Focus, Metallicize, Demon Form, Barricade, Plated Armor, Vigor and so on each count. A Power-heavy Defect or Ironclad deck gets there, as does a Watcher with her stance/mantra powers. Play a long fight, keep dropping Powers, and you'll tick over 10.

Win a single Daily Climb. The Daily Climb is a fixed seed with a set of random modifiers (some helpful, some nasty) that everyone plays that day, launched from the main menu. You just need one winning Daily run - reach and beat the Act 3 boss; the true ending isn't required. Pick a day whose modifiers look kind, play safe and steady, and you'll get it. You can attempt a fresh one every day, so there's no rush.

Get to 50 or more Strength in one combat. Ironclad: Limit Break (doubles your current Strength, and can be played repeatedly upgraded) is the engine. Build a bit of Strength via Demon Form, Inflame or Spot Weakness, then chain Limit Break to double it: 10 → 20 → 40 → 80. Two upgraded Limit Breaks off a modest base sail past 50. A high-HP enemy gives you the turns to ramp.

Get down to 3 or fewer cards total across your hand, draw and discard piles at once. The clean way is a heavy Exhaust deck (Ironclad Corruption plus exhaust payoffs, or lots of one-off exhausting cards) - exhaust your deck down until only a couple of cards are left in play. A tiny deck helps, so this pairs beautifully with the small-deck challenge Minimalist - knock both out on the same run.

Play 25 cards in a single turn - i.e. an 'infinite' combo. The principle is a thin deck where the cards you play give back the energy and card-draw they cost, so the loop never stops: cheap or 0-cost cards that draw more cards, kept afloat by an energy relic or an energy-refund card. Keep the deck as small as possible so you don't draw a dead card and stall it. Each class has its own infinite recipes (Silent draw loops, Defect Claw/All-For-One decks are popular) - build one deliberately on a run, then just keep playing until you pass 25.

Play 10 Shivs in one turn. Silent only. Shivs are the 0-cost daggers generated by cards like Blade Dance (adds 3, or 4 upgraded) and Cloak and Dagger; Storm of Steel discards your hand and gives a Shiv per card discarded. Play a couple of Shiv-generators, then throw all ten 0-cost Shivs the same turn (they cost nothing, so you can spam them). Accuracy makes the resulting turn silly. Comes naturally in a Shiv deck.

Reach 999 Block in one combat - the big brother of Impervious. You really want Barricade (Ironclad; block no longer expires between turns) so your block accumulates, then pile it up over several turns with block cards - Body Slam decks live here. Entrench (doubles current block) is the accelerator: a couple of Entrenches on a healthy total rockets you to 999. Do it against a high-HP enemy or boss that can't punch through the wall. Watcher and Defect can stack silly block too, but Ironclad Barricade is the classic.

Beat the Spire with the Watcher, the monk added after launch. She fights by switching Stances - Wrath (deal double, take double) and Calm (bonus energy when you leave it). She's the most powerful and most fragile class at once: a Wrath burst deck can delete bosses, but a careless turn in Wrath can delete you. Learn the Eruption/Vigilance stance dance and she melts the game. A Divinity + Mental Fortress deck, or a Pressure Points setup, are both strong and beginner-viable.

Kill a boss during turn 1, before it gets to act. You need a burst deck that can dump enough damage in one turn to delete a boss's full HP bar (~250 for a low-HP Act 1 boss). Realistic setups: a stacked Ironclad Strength turn (Spot Weakness/Inflame/Flex into Heavy Blade or Reaper), or a Watcher Wrath burst. Pick a low-HP boss - Slime Boss or Hexaghost at a low Ascension - build the deck across the run, then unload turn 1. Doubles up nicely with Perfect.

Complete Ascension Level 10 with any single character. Each Ascension level stacks another nasty modifier (tougher elites, less healing, weaker starting relic, and so on) and you climb one level per win on that character - so this is roughly ten wins on one class, each a notch harder. You do not need the true ending; a standard Act 3 win at Ascension 10 counts. Pick your comfiest character and grind it up. Halfway house to Ascend 20.

'The Ending' is the true final boss. After you beat the Act 3 boss, instead of leaving you take the hidden path to Act 4 and kill the Corrupt Heart. To open that path you must be carrying all three keys, collected across Acts 1-3:

• Ruby Key - skip the rest/smith at a campfire to take it instead.
• Emerald Key - beat a burning elite (the one with the green flame).
• Sapphire Key - skip the relic in a treasure chest to grab the key underneath.

Do all that as the Ironclad and put the Heart down for this one. It hits like a truck, gains Strength every turn (Beat of Death) and starts with a big Blood Shots turn, so bring a defensive deck with real burst - Strength Ironclad or a Barricade wall both work. This plus Emerald+ and Sapphire+ earns The End?.

Same as Ruby+ but as the Silent: grab all three keys (Ruby/Emerald/Sapphire) across Acts 1-3, take the Act 4 path after the Act 3 boss, and kill the Corrupt Heart. A Poison deck is the comfortable way to do it - stack enough Poison and the Heart just rots on its own while you block its hits.

The Transient is an Act 3 elite that gains huge Strength every turn but has a Fading counter - it vanishes on its own after a few turns. This wants you to actually kill it before it fades. It has a big HP pool and hits like a truck by turn 3-4, so you need front-loaded burst: block the early hits and dump as much damage as you can in the first couple of turns. Any class with a strong opening (Strength Ironclad, front-loaded Silent, Wrath Watcher) can do it. If it fades before it dies you get nothing, so prioritise damage over caution.

As Ruby+ but as the Defect. Collect the three keys, enter Act 4 and kill the Corrupt Heart. A Frost/Focus block deck tanks the Heart's big hits comfortably while your orbs chip it down; a fast Lightning swarm also works if it's online by then.

Very specific: land the killing blow on Donu with the Ironclad card Feed. Donu is one half of the Act 3 The Shapes boss pair (Donu and Deca). Feed permanently raises your max HP when it kills an enemy, and this wants that kill to be on Donu. So: play Ironclad, carry a Feed, reach the Donu & Deca fight, whittle Donu down to within Feed's damage, and finish Donu with Feed (not Deca). Leave Deca or kill it after - the important bit is the last hit on Donu being Feed.

Beat the Spire (an Act 3 win) in under 20 minutes of in-run time. Speed comes from ending fights fast and not dawdling on maps and menus. An aggressive high-damage deck (Silent Poison or Ironclad Strength) that bursts fights down helps, and a low Ascension keeps enemy HP low. Skip card rewards you don't need (fewer choices = less time), beeline the shortest map path, and play briskly. A run seeded with an early damage engine makes this comfortable - the timer is generous if you're not dithering.

The meta-achievement for the true ending: complete the Ending (kill the Corrupt Heart in Act 4) with the Ironclad, the Silent AND the Defect - i.e. earn Ruby+, Emerald+ and Sapphire+. The Watcher is not required (the achievement predates her), so Amethyst+ is a nice bonus rather than a requirement. Each of those three explains the collect-all-three-keys route into Act 4.

As Ruby+ but as the Watcher. Grab the three keys, take the Act 4 path and kill the Corrupt Heart. The Watcher's Wrath burst can delete the Heart in a turn or two - just make sure you can survive Beat of Death and its big attack, ideally by sitting in Calm and bursting into Wrath the turn you go off. Not required for The End? (that one only needs the three original characters), so this is a bonus.

Reach 25 or more Focus (the Defect's orb-power stat) in a single fight. Stack Focus cards - Defragment (+1 each), Biased Cognition (+4 up front) and Consume (+2, costs an orb slot) - plus any Focus relics. Play them over a longer fight and you'll cross 25. Happens naturally in a Focus-scaling Defect deck; a drawn-out boss fight gives you the turns to get there.

Channel 9 Plasma orbs (the energy orbs) in a single turn - Defect only, and one of the fiddlier feats. The main Plasma source is Meteor Strike (channels 3 Plasma), so you're looking at playing it several times in one turn - three casts gets you the 9 - which means a big energy setup: energy relics plus energy-gain so you can afford the 5-cost card repeatedly. Chaos (channels a random orb) can chip in the odd Plasma too. Build a deliberate high-energy Meteor Strike run for this rather than hoping it happens.

Win with a deck of 5 cards or fewer. You start with 10-12 cards, so this is all about aggressive removal: take card-removal at every shop, and every Purge/removal event you can, skip almost all card rewards, and lean on relics and potions for power instead of cards. A couple of strong cards plus good relics carries it. Pairs perfectly with Purity and Who Needs Relics? on one minimalist run, and a lower Ascension makes the thin deck survivable.

Complete Ascension Level 20, the top of the mountain, with any one character. You reach it by winning at each Ascension level from 11 through 20 on that character (A20 famously adds a brutal double Act-boss fight among other things), so it's the single biggest time-and-skill sink on the list. Only a standard Act 3 win at A20 is needed, not the true ending. Do it on whichever class you've mastered - Ironclad and Defect are the popular, forgiving picks. Take your time; nothing here is missable so you can grind the climb run by run.

Win with a deck of only Common cards. Your Basic starting cards (Strike/Defend) are fine - it's Uncommon and Rare cards you can't have in the deck when you win, so decline every Uncommon/Rare reward (and any Colourless Uncommon/Rare from shops and events) and only ever pick Commons. Remove starting bloat as normal. Relics can be any rarity, so lean hard on strong relics. Comfortable on a lower Ascension with a solid Common backbone - Silent Poison commons or an Ironclad Strength core both hold up.

Win while holding just one relic. You keep your starting relic (that's your one), so the run is about not picking up any more. The big catch: elite fights auto-grant a relic you can't decline, so you must avoid every elite - route around them on the map. Skip relic rewards, don't open treasure chests (take the skip), dodge relic events, skip the boss relic reward, and at shops only ever buy cards/potions/removal - never relics. It's very doable on a lower Ascension; just be disciplined about leaving relics on the floor. Combine with Minimalist and Purity for a triple-dip minimalist run.

The completion cap - it pops automatically the instant every other achievement on this list is unlocked. Nothing to do but finish the other 45; Ascend 20 (Ascension 20) and the challenge wins (Minimalist, Who Needs Relics?, Speed Climber) will almost certainly be your last few. Grats on the full clear when it lands :)