The Oath of the Unseen unlocks only after Chronos is defeated at least once, and it lives in the Training Ground between the Underworld and Surface gateways. Activating Vows raises Fear, which is the measure of adversity — and the number players actually optimise for, because Testaments of Night and The Night’s Champion require hitting specific Fear thresholds.
That is why “best vows for 16 fear” and “best vows for 32 fear” are the searches that matter: you are not choosing the hardest Vows, you are choosing the cheapest Fear per unit of actual difficulty. All values below come from the Hades Wiki’s Oath of the Unseen page.
All 17 Vows, by Fear cost
| Vow | Fear | Effect |
|---|---|---|
| Vow of Wards | 2 | All foes have 1 / 2 Shield |
| Vow of Return | 2 | Most slain foes have +25% / +50% chance to become a Revenant |
| Vow of Debt | 2 | All items that cost Gold become more expensive |
| Vow of Shadow | 2 | All Warden encounters contain no fewer than 1 Shadow Servant |
| Vow of Hubris | 2 | After choosing a Boon, Prime 3 / 6 Magick for each Rarity above Common |
| Vow of Denial | 2 | After choosing a Boon, 2 unpicked blessings will not appear again |
| Vow of Grit | 3 | All foes have +10% / +20% / +30% Health |
| Vow of Hordes | 3 | Most encounters have +20% / +40% / +60% more foes |
| Vow of Menace | 3 | Most foes have a 10% / 25% chance to be from the next Region |
| Vow of Forfeit | 3 | The first 1 Boon in each Region becomes an Onion instead |
| Vow of Scars | 4 | Healing effects are 75% / 50% / 0% effective |
| Vow of Pain | 5 | All foes deal +20% / +60% / +100% damage |
| Vow of Fangs | 5 | Most foes with Armor also have 1 / 2 random Perks |
| Vow of Void | 5 | You have access to 60% / 40% / 20% / 0% of your Grasp for Arcana |
| Vow of Frenzy | 6 | All foes are +20% / +40% faster |
| Vow of Time | 6 | You have 09:00 / 07:00 / 05:00 to fight through each Region |
| Vow of Rivals | 12 | The Guardians of the first 1 / 2 / 3 / 4 Regions are stronger |
Vow of Rivals at 12 Fear is the single most expensive Vow in the game — more than double the next highest. It is also the only one that changes bosses rather than regular foes.
Which Vows are cheap and which are lethal
The wiki makes the key point directly: many Vows are nearly ineffective against one weapon build but extremely difficult against another. Fear cost is a price, not a difficulty rating, and the two diverge sharply.
Cheap relative to their Fear cost:
- Vow of Denial (2) — losing 2 unpicked blessings hurts your consistency, not your survival.
- Vow of Debt (2) — a gold tax, and gold is the most renewable resource in a run.
- Vow of Hubris (2) — Primes Magick based on boon rarity, which only bites if your build depends on Magick.
- Vow of Wards (2) — 1 or 2 Shield on enemies is a small tax on your damage output.
Expensive relative to their Fear cost:
- Vow of Void (5) — cutting your Grasp to 60%, 40% or 20% disables Arcana cards outright. If your build is Arcana-dependent, this is the most dangerous Vow on the list for its price.
- Vow of Time (6) — a hard clock per region punishes slow, defensive play specifically.
- Vow of Frenzy (6) — faster foes break parry and dash timing, which is the mechanic most players rely on.
- Vow of Scars (4) — at rank 3, healing is 0% effective. That removes an entire defensive pillar.
Hitting the Fear thresholds
Because every Vow has a published Fear value, you can build to a threshold deliberately rather than by feel. These combinations use the real costs above:
16 Fear — the first serious threshold. Take the four cheapest that do not touch your core plan: Wards (2) + Return (2) + Hubris (2) + Denial (2) + Debt (2) + Shadow (2) = 12, then Grit (3) = 15, then Forfeit (3) = 18. To land exactly on 16, swap Forfeit for Scars-less options: Wards 2 + Return 2 + Hubris 2 + Denial 2 + Debt 2 + Shadow 2 + Grit 3 + Hordes 3 = 16 exactly.
24 Fear. Start from the 16 above and add Menace (3) = 19 and Forfeit (3) = 22, then Return’s second rank or Debt adjustments bring it to 24. The principle is the same: fill with 2- and 3-cost Vows and avoid Pain, Frenzy, Time, Void and Rivals.
32 Fear. At this point the cheap Vows are exhausted — all six 2-cost Vows plus all four 3-cost Vows total 24 — so you must take on real difficulty. Adding Pain (5) and Scars (4) reaches 33; swapping one 3-cost out for Fangs (5) instead lands closer to 32. Expect Vow of Pain’s +20% enemy damage at rank 1 to be the first addition that genuinely changes how you play.
The arithmetic worth remembering: the six 2-cost Vows total 12 Fear and the four 3-cost Vows total 12 Fear. That means 24 Fear is reachable using only Vows costing 2 and 3, with no Vow above 3 taken at all — which is why 24 is the last threshold that can be climbed without accepting a run-changing modifier.
Circe can remove a Vow without lowering Fear
This is the most useful mechanic on the page and the one players miss. Circe’s Black Night Banishment can temporarily remove a Vow for a night, and it does so without lowering your total Fear value.
That means you can stack Fear to hit a Testament threshold and then banish the Vow that would actually have ruined your run — keeping the reward while dropping the difficulty. The wiki notes this is particularly useful for the Fear thresholds required by Testaments of Night and The Night’s Champion, with the caveat that some Vows have unique interactions when removed.
Vows that interact with your boons
Three Vows touch the boon system specifically, and they behave very differently:
- Vow of Hubris taxes you per rarity above Common — so a legendary-heavy build pays much more than a common-heavy one.
- Vow of Denial removes unpicked blessings from the pool after each choice, which narrows your options but makes the boons you do want more predictable.
- Vow of Forfeit turns a Region’s first Boon into an Onion, which is a direct loss of a boon slot.
Several Vows also share a synergy note: Vow of Pain, Grit, Wards and Frenzy all apply to enemies affected by Night Bloom and Sun Worshiper. Vow of Pain synergises with the Devotion upgrade, and Vow of Frenzy with the Rigor upgrade — so if you are running those, these Vows cost you more than their Fear number suggests.
For the wider Fear system and how to climb it in steps, see the nightmare guide. If you need more materials to fund the Vow climb itself, the resources guide covers what to farm, and best weapons tier list ranks the weapons you will be running these Vows with. Boon choices under these constraints are covered in the best boons tier list and gods overview, and Arcana planning — which Vow of Void directly attacks — is in the Arcana cards guide.