Level up or artifact: reading the floor

A level-up and an artifact are not two versions of the same reward, and the difference is not subtle once you know what to look at: a level pays into your save as well as into your run, and an artifact only pays into your run.

Because the map shows you what the rooms ahead are offering before you walk into any of them, choosing between them is the first real decision on every floor. Here is what each kind of room is actually handing over.

What a level-up gives you

Experience is not a stat. It is a delivery mechanism for three separate things:

• Health. Levelling restores HP. The village tree sells Level Up Restoration to raise how much comes back, and hard mode’s Deterioration shard exists specifically to cut it — two systems built around the same number, which tells you how much the game expects you to lean on it. In practice a level-up room on a floor where you are hurt is a healing room.
• Sapphires. Levelling up is one of the ways Sapphires arrive, alongside treasure chests and bosses. Sapphires are the only thing in a run that outlives it, since they are what the Destiny Inscription is bought with.
• Bag space. You gain an inventory slot every second level. A run starts at 24 slots and can reach 42, and every one of those slots is somewhere an artifact or a tablet can sit for the rest of the run.

That last one is the reason experience is undervalued by new players. An artifact is one effect. A slot is the place effects go, and it keeps paying every time you pick something up later. Early on a floor, when you are still collecting, a slot is often worth more than the card you would have put in it.

What an item reward gives you

An item room offers you a choice between artifacts and tablets, and the choice itself is a resource that several systems bend:

• Dice reroll the offer. They are the currency for exactly this — throw back what you were shown and ask again, for other items, weapons or miracles. You can buy dice at the tree, the Willpower talent starts you with two more at level 5, and Wisdom at level 20 gives you one free item-reward reroll outright.
• Ingenuity at level 10 adds a choice to every weapon, item and miracle offer, which is the same effect from the other direction: more cards seen, fewer runs decided by a bad screen.
• Hard mode takes choices away. The Dizziness shard removes one or two artifact and tablet choices per offer. If you are planning a hard-mode run, see what that costs you on the hard-mode planner.
• Fruit skewers bias what appears. Each combo category has its own fruit, and selecting fruits raises the chance that related combo items show up as rewards — or lowers the chance of combos you do not want. That is the closest thing the game gives you to choosing your own drops, and it only helps if you have already decided which combo you are building.

Tablets arrive through item rewards too, which is worth remembering because the Alchemy combo turns exactly that event into a free potion: obtain a tablet from an item reward and it crafts one for you.

The other rooms, and what each is for

Weapon rooms upgrade the weapon you are carrying. Every branch is two upgrades deep — a first upgrade and then a second built on top of it — so a weapon room passed over early is a second upgrade you will not reach later in the run. The full shape of all six branches is on the weapon upgrade map, and it is worth knowing where your first pick leads before you take it.

Enchanting rooms raise an artifact’s level. Check the ceiling before you commit: an artifact already at its maximum level cannot be enchanted, and neither can one whose maximum level is 0. Walking into an altar holding nothing but finished artifacts is a wasted room.

Miracle rooms grant special abilities and items — and only one miracle can be active at a time, so this is a replace-or-keep decision rather than a collect-them-all one.

Merchants sell for Leaf, the in-run money, at prices that move with Barter. The Negotiation combo is built around that: two artifacts of the category give Barter +10 and Leaf Drop +15%.

Boss rooms end the floor. Bosses pay Sapphires and drop tablets, which is why a boss is worth reaching even on a run that is clearly not going to finish the chapter.

How to actually route a floor

A workable order of priorities, from the top of a run downwards:

1. Early, take what compounds. Levels, and therefore slots. Anything that makes the rest of the floor bigger is worth more than a single effect while there is still floor left.
2. Take the step on your ladder. Once you have decided which category you are stacking, the artifact that completes a threshold beats a rarer artifact that does not. Artifact combos has the thresholds for all twenty categories.
3. Take the weapon upgrade before the run is half over, since the second one needs the first.
4. Take healing when you are low, not when you are full. A level-up room is a heal, and a heal you did not need is a reward you did not collect.
5. Late in a run, take the immediate power. A slot with nothing left to put in it is worth nothing, and neither is a build path with no floors left to grow on.

The reason this ordering works is that a slot, a level and a tablet all pay out through the grid, and the grid is what turns a pile of artifacts into a run that scales — which is the subject of bag basics. When you want to see whether a card you are being offered would actually fit, lay the run out in the bag planner, and when you just want to check what a card does, everything is on its page in the item database.