🏛️ Ancient Boons & Alternate Chapters: Complete System Guide
📅 Updated Jun 3, 2026 · ⏱️ 11 min read · 🏷️ Mechanics v0.106.1
Ancient Boons are STS2's new chapter-variant system — replacing the STS1 Act structure with dynamic, choice-based alternate chapters. At the start of Acts 2 and 3, you choose between the standard chapter and an Ancient chapter, each offering unique enemies, events, and a powerful Ancient Boon reward on completion.
How Alternate Chapters Work
At the start of Act 2 and Act 3, you face a fork:
- Standard Chapter: Normal enemies, events, and boss
- Ancient Chapter: Harder enemies (Ancient variants), unique ? events, different boss, but rewards an Ancient Boon on completion
Ancient chapters are risk/reward: harder fights + a powerful permanent buff. The question isn't just "which boon is best" — it's "can I survive the Ancient chapter with my current deck?"
All 8 Ancient Boons (Ranked S-D)
S-Tier — Run-Defining
| Boon | Effect | Best Characters |
|---|---|---|
| Ancient Vitality | +15 Max HP. Heal 10 HP after each boss. | All. Universal value, no conditions. The safest pick. |
| Ancient Focus | Start each combat with +1 Focus, +1 Strength, +1 Dexterity. | Defect (Focus), Ironclad (Strength), Silent (Dexterity). Triple stat buff for free. |
| Ancient Wisdom | At the start of each turn, draw 1 additional card. | Silent, Defect, Regent. Extra draw every turn effectively reduces deck size by 20%. |
A-Tier — Strong and Consistent
| Boon | Effect | Best For |
|---|---|---|
| Ancient Arsenal | Choose and obtain a Rare relic. | Any character wanting a specific relic build-around. |
| Ancient Blessing | Upgrade 3 random cards. Heal to full HP. | Decks with many unupgraded cards. Best mid-Act 2 pick. |
| Ancient Wealth | Gain 300 Gold. All shop prices reduced by 25% for the rest of the run. | Economy-focused runs. Enables 3-4 shop purchases. |
B-Tier — Situational
| Boon | Effect | When to Take |
|---|---|---|
| Ancient Fury | Deal 50% more damage on the first turn of combat. | Silent Sly (burst), Regent Starfall (turn 1 nuke). Useless for Frost Defect. |
| Ancient Fortitude | Gain 15 Block at the start of each combat. Block does not decay between turns. | Setup-heavy builds that need a safe first turn (Necrobinder Summon, Defect). |
When to Take the Ancient Route (vs Safe Route)
Take Ancient Chapter IF:
- ✅ Your deck is ahead of the curve (beat last elite with 60%+ HP)
- ✅ You have sustain/recovery (healing relic, sustain cards)
- ✅ Your deck counters Ancient enemy types (AOE for swarm fights)
- ✅ The boon directly synergizes with your build (Focus boon for Defect)
Take Standard Chapter IF:
- ❌ You're low HP (below 50%) or just scraped by the last boss
- ❌ Your deck needs time to scale and Ancient enemies will punish you
- ❌ The offered boon doesn't help your build (Fury boon for Frost Defect)
- ❌ You're playing Defect with no Frost setup — Ancient elites will destroy you
Ancient Chapter Enemy Types
| Enemy | Threat | Counter |
|---|---|---|
| Ancient Slime (Large) | Splits into 2 Medium on death, Medium splits into 2 Small | AOE damage, multi-hit attacks |
| Ancient Gremlin Leader | Summons 3 Gremlins every 2 turns, buffs all minions | Focus fire the Leader, ignore minions |
| Ancient Looter | Steals 30 gold, then flees after 3 turns | Burst damage in 2 turns |
| Ancient Sentry Trio | 3 Sentries that buff each other on death | Kill simultaneously or AOE |
Per-Character Boon Priority
| Character | 1st Choice | 2nd Choice | 3rd Choice |
|---|---|---|---|
| Ironclad | Ancient Focus (Strength + Dex) | Ancient Vitality | Ancient Fury |
| Silent | Ancient Wisdom (draw) | Ancient Focus (Dexterity) | Ancient Vitality |
| Defect | Ancient Focus (Focus!) | Ancient Wisdom | Ancient Vitality |
| Necrobinder | Ancient Vitality | Ancient Fortitude | Ancient Arsenal |
| Regent | Ancient Wisdom | Ancient Focus | Ancient Arsenal |
🎯 Key Takeaway: Ancient Boons are the single largest power spike you can get mid-run. Always evaluate if you can survive the Ancient chapter — the boon is worth the risk if your deck is healthy. Ancient Focus is the universal best boon for Defect/Ironclad/Silent. Don't greed Ancient if you're limping.