Build a Base and Steal AFK offline income — the 24/72h cap, DR bands, and the calculator

What AFK offline income means

When you log out of Build a Base and Steal, your placed pets keep producing cash. On next login, the game shows an “offline cash” pop-up with the accumulated amount, which you then collect manually (or automatically if you own the Auto Collect gamepass).

The catch is the cap. Build a Base and Steal stops accumulating offline cash after:

• 24 hours for free players.
• 72 hours for Premium pass holders (scenario field — Build a Base and Steal does not currently publish a Premium Pass).

Cash above the cap does not accumulate; you cannot “save up” offline hours.

The 10/20/30 diminishing-returns bands

The placed pet roster applies a diminishing-returns multiplier to your total cash/second. The bands are:

The bands exist to keep high-tier players from runaway-roster economies. The trade-off:

• Bigger roster = more raw cash. Doubling your roster from 10 to 20 pets roughly doubles your raw cash/second.
• Bigger roster = lower per-pet yield. Each new pet beyond 10 contributes only 85% as much as the pet before, and each beyond 20 contributes 70%.

The 30-pet cap matches the visible base limit. Any pet beyond 30 contributes only 55% — usually a sign you should park the weakest pet rather than place it.

The 24/72h cap and the AFK Offline Income Calculator

The AFK Offline Income Calculator models your offline cash up to the 24-hour free cap or the 72-hour Premium cap. The calculator needs five inputs:

• Total roster cash/second.
• Number of placed pets on the base (0–30).
• Current Rebirth tier (0–8).
• Permanent Luck multiplier (1 default).
• Event multiplier (1 default).
• Share of the cap horizon you actually spent offline (0–1).

It returns:

• Projected offline cash at the chosen cap.
• DR band breakdown (which band each pet count contributes to).
• Marginal $/hr ranking (sorted by marginal hourly contribution after the DR band multiplier).
• 24-hour cumulative sparkline.
• Premium-cap extra offline cash (the breakeven in cash terms only).
• “Pets to consider removing” — the lowest $/s pets whose removal would push the roster up one DR band.
• Engine warnings.

Reading the marginal $/hr ranking

The ranking sorts your placed pets by marginal $/hr after the DR band multiplier. A pet at the bottom of the list is the one whose removal hurts your effective cash the least. If that pet sits right above a band threshold, removing it lifts every other pet into the previous band (a “band up”) and is usually worth more than the pet itself.

For example, if you have 21 pets and the weakest one is a Mythic contributing $100/s raw, removing it:

• Drops your roster to 20 pets (still in band 1, 85%).
• Saves you 1 placed slot for a stronger pet.

But if you have 31 pets (band 3, 55%), removing the weakest pet:

• Drops your roster to 30 pets (band 2, 70%).
• Boosts every remaining pet’s effective contribution by 70/55 = +27%.

The calculator surfaces this scenario as a “pets to consider removing” card.

Premium-pass breakeven — extra offline cash, not Robux

Build a Base and Steal does not currently publish a Premium Pass. The 72h cap is therefore offered as a scenario field. The calculator still tells you the extra offline cash you would earn if a Premium cap existed:

premium_breakeven = (cash/second × 72h × offline_share) - (cash/second × 24h × offline_share)
                 = cash/second × 48h × offline_share

The engine refuses to convert that cash into Robux per cash because Roblox’s rate varies by region and is not published in-game. Compare the cash breakeven against whatever Robux price a future Premium Pass might carry.

Why the private-server AFK transfer bug matters here

The private-server AFK transfer bug observed across the steal-sim family (see Private Server Risk) can wipe your accumulated offline cash if your session is transferred to a public server while AFK. Until that bug is ruled out for Build a Base and Steal specifically:

• Limit your offline horizon to the 24-hour free cap on a public server.
• If you’re on a private server, manually log out before going AFK.
• Use the calculator to model your expected offline cash under the 24h cap and budget accordingly.

Sources and verification

• Sportskeeda Rebirth guide: https://www.sportskeeda.com/roblox-news/build-base-steal-rebirth-guide
• ProGameGuides beginner guide: https://progameguides.com/guides/build-a-base-and-steal-beginners-guide/
• earnaldo Robux hub: https://earnaldo.com/blog/build-a-base-and-steal-free-robux-guide
• Official Roblox game page: https://www.roblox.com/games/132016691802922/Build-a-Base-and-Steal

What to read next

• Rebirth Guide — model the NPV delta of each Rebirth tier with the calculator.
• Pet List — every named pet by rarity tier.
• Private Server Risk — the API-vs-description conflict and the AFK transfer bug.