Common Shop

Core Dust drop chances, prices, and refresh costs in the Common Shop. All numbers were recorded from the game.

Slot probabilities

The shop has 10 slots, and only slots 1 to 3 can roll Core Dust. You get two free pages a day, since the shop fills for free at the start of the day and the first refresh is also free. Paid refreshes then cost 100, 200, 300, and so on, rising 100 gems each time with no cap. Core Dust amounts are hours except slot 1’s flat ×30 item.

Slot 1 (reference only, not used in calculations)

ChanceCore DustPriceNote
1/3 (33.3333%)30Freeraw Core Dust x30, not dust-hours

Rest of the time: 60k credits.

Slot 2

ChanceCore DustPriceNote
9/186 (4.8387%)1150,000 creditsfull price
6/186 (3.2258%)1120,000 credits20% off
3/186 (1.6129%)190,000 credits40% off
21/186 (11.2903%)290 gemsfull price
14/186 (7.5269%)272 gems20% off
7/186 (3.7634%)254 gems40% off

Rest of the time: battle data set cases, credit cases, and battle data sets.

Slot 3

ChanceCore DustPriceNote
9/162 (5.5556%)1150,000 creditsfull price
6/162 (3.7037%)1120,000 credits20% off
3/162 (1.8519%)190,000 credits40% off
21/162 (12.963%)3150 gemsfull price
14/162 (8.642%)3120 gems20% off
7/162 (4.321%)390 gems40% off

Rest of the time: battle data set cases and credit cases.

Slots 4 to 10 never hold Core Dust. They sell miscellaneous items, and none are recommended (slot 5’s Profile Custom Packs are cosmetics, so buy them only if you’re into that).

Deal efficiency

This table ranks the six gem-priced deals by what a gem buys. Deeper discounts on the same item are better, and slot 2’s smaller box beats slot 3’s at every discount tier.

DealDust (hrs)Gem costHrs / gem
Slot 2, 40% off2540.037
Slot 3, 40% off3900.033
Slot 2, 20% off2720.028
Slot 3, 20% off31200.025
Slot 2, full price2900.022
Slot 3, full price31500.020

For comparison, event stage entries convert at 0.200 hrs/gem and the first paid Outpost Defense wipeout at 0.040. The shop’s best deal sits below both.

Guide

What to buy

Slots 2 and 3 can roll Core Dust boxes priced in credits or in gems. Always buy the credit ones. Slot 1 gives out more free credits than those boxes cost, so that dust is basically free. For the gem deals, use the efficiency table above. A deal’s rate is its dust divided by its price, and slot 2’s 40% off box (2 hrs for 54 gems, 0.037 hrs/gem) is the best deal in the shop.

Buying by policy, not by page

Each slot rolls on its own at the chances above, so you never know what a page will show. Decide ahead of time which deals you always buy. Pick a cutoff in the efficiency table and buy everything at or above it whenever it appears. To get a rule’s expected cost and dust per page, multiply each deal’s price and dust by its appearance chance and add up everything it covers. A cutoff includes every more efficient deal above it.

What a refresh buys

Each refresh shows another page. Its credit-priced offers provide about 0.21 hrs on average without spending more gems, while any gem deals still cost their usual prices. The first paid refresh returns roughly 0.002 hrs per gem, and every later refresh is worse. Use your two free pages every day. Paid refreshes are the worst gems-to-dust conversion this site tracks.

How this feeds the planner

The planner compares shop deals with the other Core Dust sources by hrs/gem. The shop’s best deals rank below the first paid Outpost Defense wipeout and far below event entries, so the shop enters larger budgets with the 40%-off deals first.