Vault of the Void Beginner Guide: 20-Card Decks, Purge, and Threat Resolution
Edition: Shared systems in normal PC (Steam) play. Exceptions specific to additional classes or Challenge Coins are outside this guide's scope. Sources checked: October 14, 2026. No follow-up testing through actual gameplay has been performed.
First distinguish Threat that will deal damage at the end of this turn from Threat added by the enemies' next actions. Each card can be played, kept, or Purged. You can rebuild your 20-card deck from the backpack after battle, so every card you pick up does not have to become a permanent member of the combat deck.
Before battle: rebuild your 20-card deck from the backpack
- Check the enemies in the next battle and the displayed reward. Consider whether to aim for a short or longer fight, based on enemies with dangerous attacks or buffs.
- On the deck screen, distinguish your 20-card combat deck from the cards in your backpack. Consider replacing less useful cards with new pickups.
- Check the Block you need, the cost of your attacks, and how to handle status effects. Do not take a deck of 20 attack cards straight into a tough fight.
- When adding a Void Stone, read the target card, the stone's effect, and the rules after it is socketed. Choose based on whether you want to use that card repeatedly in the next battle or have it immediately at the start.
- Confirm that your deck has 20 cards before entering battle. Do not assume you can summon any card you want from the backpack during combat.
Choose whether to play, keep, or Purge each card in your hand
| Choice | What happens | Example decision |
|---|---|---|
| Play it now | Pay the Energy shown on the card and resolve its effect | Prioritize Block that clears current Threat and cards that kill enemies preparing to attack |
| Keep it in hand | Carry the card into the next turn | Save a Block card you do not need now if you expect to receive a large amount of Threat next turn |
| Purge it | Discard it from your hand, normally gaining 1 Energy. Follow its description if it has a specific Purge effect | Turn a card you will not use in this sequence into a resource to pay for a card you need |
| Remove it from the deck before battle | Change the lineup using the backpack | Rebuild the 20-card deck. This is separate from Purge during battle; Purging a card alone does not permanently remove it |
- Cards in your hand and Energy carry over to the next turn. However, the normal start-of-turn draw only fills your hand to five cards, so keeping more cards leaves fewer slots for new draws.
The first two turns: check Threat before spending resources
The following example teaches normal Threat resolution. If enemy-specific or Purge effects change the numbers, prioritize the on-screen prediction.
- At the start of turn one, check whether you already have Threat. Normally, the enemies have not attacked yet, so you do not need to spend all your Block cards just because you see their next intended attacks.
- Count the enemies you can kill now and the Energy your attack cards need. Purge unused cards, then play the attacks you need. Check any card-specific Purge effect before discarding the card.
- Decide whether to keep Block cards for the next turn. Check that keeping too many cards is not filling your draw slots, then end the turn.
- After the enemies attack, read the Threat actually applied on turn two. This Threat will deal damage when your current turn ends.
- Reserve and pay the cost of the Block you need, then check the predicted remaining Threat. Use leftover resources for attacks and buffs. Killing an enemy now does not remove Threat it applied on the previous turn.
- Before ending the turn, separately recheck current Threat and the enemies' next intended attacks. In reinforcement battles, also watch for replacements immediately after a kill and buffs applied to other enemies.
Calculation examples: keep Threat, Block, and Energy separate
| Example situation | Action and result | Caution |
|---|---|---|
| You currently have 12 Threat and gain 8 Block this turn | With no other effects, 4 Threat remains. Look for another way to prevent the 4 damage at the end of the turn | This is an example calculation explaining the system, not a fixed value for a particular real enemy |
| You have 1 Energy and want to play a card costing 3 | Purging two unused cards normally provides enough resources to pay the total of 3 | If a card's Purge effect causes other changes, include those when checking the sequence |
| You keep three cards in hand for the next turn | Normally, you draw only two new cards | If you have no plan to use the three kept cards, Purge them to secure resources and room for new choices |
| You killed an enemy, but earlier Threat remains | Resolve current Threat with Block before ending the turn | Killing an enemy and clearing Threat already received are separate things |
Void Stone examples: choose by the target card's role
| Stone and combination | Intended effect | What to check before using it |
|---|---|---|
| Green Void Stone with a buff card you want early | Plan to use it from the start of battle through Rig | You still need Energy to play the buff. Drawing it at the start does not mean playing it for free |
| Blue Void Stone with a card that has Recur | Link card retrieval with drawing. Discard effects on cards you discard are another possible part of the combination | Decide what to retrieve, what to discard, and which effect you want before using it. Do not confuse Purge effects with Discard effects |
| Black Void Stone with an important debuff card | Use it to repeat the same card's effect | Assign it to an effect you will also need against later tough enemies, rather than socketing it simply because it is spare |
- This is not a current numerical list for every color or card. Check the stone's description and class-specific exceptions in your game, and do not assume every class can freely move socketed stones.
Use common mistakes to improve your next battle
| Symptom | Where to look for the cause | What to change next |
|---|---|---|
| You take damage immediately after killing an enemy | Threat remaining at the end of the turn | Check Threat before and after attacking, and keep resources to pay for Block |
| You have only Block cards and cannot draw attacks | The hand you kept from the previous turn | Distinguish keeping one card you need from holding on to everything |
| You have a powerful card but cannot play it | Too few cards available to Purge for its cost | Decide which actions you need from your current hand first, then Purge unused cards |
| Newly collected cards make your deck harder to use | The lineup of your 20-card combat deck | Swap cards with the backpack outside battle to restore a 20-card deck suited to the current enemies |
Frequently asked questions
Does Purge permanently remove a card?
It is separate from permanent removal. In battle, it converts cards in your hand into resources. To change your 20-card combat deck, swap cards with the backpack outside battle.
Should I Block on the same turn I see an enemy's attack?
Normally, you resolve Threat applied by an enemy's attack with Block on your next turn. Distinguish the next intended attack from Threat that will deal damage at the end of the current turn.