Boss Guide: Every Act & Rift

Boss Progression at a Glance

Most failed runs in this incremental card-battler don't collapse because your collection is bad. They collapse because you walked into a boss with the wrong army and no upgrade plan. This Booster Pack Heroes boss guide maps every major wall from the Chapter 1 fight to Null the Undefined, so you can prepare instead of guessing. Read each encounter like a checklist: identify the threat, buy the answer, then push.

If you are brand new, the first thing to understand is that bosses are gates, not just big monsters. Every cleared boss unlocks a new pack tier or advances the Gate to the Stars counter, and those unlocks matter far more than squeezing one extra chapter out of a weak build.

Cracking the Chapter 1 Boss

Your opening build is fragile by design. After the first defeat, spend your first Mastery on Tower HP, buy a Basic Pack from the Shop, and open it immediately so a defender is standing before the trash waves arrive. Your first Shop holds 3 Coins and a Basic Pack costs 2, so the opening quest asking you to open two Basic Packs is worth prioritizing — it adds +1 to your regular income and instantly widens your options.

The Chapter 1 boss punishes clumped heroes with area damage, so "more bodies" is not a strategy on its own. Diagnose your last attempt before spending again:

Tomes deserve special attention here. Thunderstorm, for example, fires thunderbolts only while its duration lasts. Firing it the second you can afford it may clear a nasty wave and leave you with nothing when the boss walks in. Save it for the moment your army is actually losing ground.

Clearing this fight unlocks Advanced Packs and moves the Gate to the Stars to 1/3. Chapters 2 and 3 follow the same rhythm: Eyes without Hunger demands sustained damage rather than burst, and The Witch from the Abyss closes out the gate requirement. That is the first third of this Booster Pack Heroes boss guide wrapped in three fights — after 3/3, interact with the gate and choose Begin Act Two.

Act 2: Iron Legion, Relics, and Foil Boss Replays

Act 2 resets your Skill Tree. Folium upgrades, your unspent Folium balance, and your Collection all survive, so don't panic-spend Folium before entering the gate. What does change is your power level: heroes you had pumped up in Act 1 feel weak again, and the Iron Legion hits differently than Cavelings did.

Rebuild in this order: tower HP, starting damage, income quests, then Relics. Your first Relic Pack arrives during Act 2, and one early example is worth understanding — every third cursor attack deals double damage and stuns everything it hits. That is a free combat engine that doesn't need a hero slot.

Chapter 5 is where a lot of players stall. Invisible attackers and fast enemies slip past your front line and chew the tower while your army is busy elsewhere. Aegis Ward absorbs that first burst and answers with a full-screen Shockwave, which buys exactly the time you need to clear the rush. Once you can survive the opening, stop buying income and start converting Mastery into attack power — the Chapter 7 Iron Legion is a damage check, not a wealth check.

Chapter Select opens up around this point too, letting you replay cleared chapters against Foil versions of their bosses. These are harder, not easier. Chapter 4's Foil Apogre carries 2,500 HP and pays 4 Folium, and it can still flatten a build that has already reached Chapter 5. Treat Foil replays as a second job you take on once your main campaign is comfortable.

Act 3 Rift Bosses: Nature, Death, Frost, Chaos

Act 3 stops being a straight line. Rifts interrupt chapters with modifiers you cannot out-damage, and higher Prestige versions of earlier chapters become mandatory. This is the section where a Booster Pack Heroes boss guide earns its keep, because brute force stops working.

Nature is the cleanest teaching moment: with Bushes active, your cursor heals instead of hitting, so every point of offense has to come from your board. Death asks you to over-recruit before the fight starts. Frost rewards patience — smashing the ice before you open anything avoids wasting a purchase. Chaos is the opposite, punishing over-upgrading through Momentum, so buy only what your board needs.

Watch your Prestige selection carefully. A chapter completed at Prestige 1 does not satisfy a Prestige 2 objective, and the late Act 3 route specifically requires Chapter 4 cleared on Prestige 2 before the final gate opens.

The Final Boss and Endgame Checklist

Opening the Rift to the Plane of Chaos unlocks Point of no Return, which sounds final but is not the ending. Null the Undefined is the real fight, and it changes form mid-battle, so your damage needs to keep landing while the target shifts. Cosmic summons and temporary offensive effects are the tools that close it out.

Beating Null completes Chapter 15 and the Plane of Chaos and awards The First Fracture. Then return to the Gate to the Stars and select Complete this act. Progress is preserved, Act Three Complete appears, and the game rolls The End. You can keep playing afterward to chase remaining Foil monsters, Relics, and Collection entries.

One quiet rule that saves hours: Chapter Select only advances monster quests for the chapter you actually selected. If a kill-counter objective refuses to budge, check which enemy it names and replay the chapter that contains it rather than farming your current one.

FAQ

How long is the route from first boss to the ending in this Booster Pack Heroes boss guide? Three chapters open the gate to Act 2, Act 2 ends with the Chapter 7 Iron Legion, and Act 3 runs through the four Rifts to Null the Undefined in Chapter 15 — followed by one last interaction at the Gate to the Stars to register the ending.

Do I lose progress when Act 2 begins? Only your Skill Tree resets. Folium upgrades, your Folium balance, and your Collection carry over, so there is no need to drain your Folium before stepping through the gate.

What is the best way to farm Folium? Foil Boss replays through Chapter Select. Chapter 4's Foil Apogre gives 4 Folium per clear at 2,500 HP, which is a comfortable target once your Act 2 build is stable.

Why is my monster quest stuck at the same number? Because the selected chapter doesn't contain that monster. Replays only credit kills for enemies present in the chapter you choose, so match the objective to the right map.

Stick to the pattern in this Booster Pack Heroes boss guide — read the encounter, buy the counter, then push — and the walls that felt impossible become a checklist you tick off one Act at a time. Every pack you open along the way, from a Basic Pack to a Cosmic summon, feeds that next attempt.