Build a Base and Steal Rebirth guide — the 11-tier ladder, ROI math, and the calculator

What Rebirth does

Rebirth is the long-term progression arc in Build a Base and Steal. When you Rebirth:

1. Your base is reset.
2. Your cash balance is reset.
3. Your pet roster is wiped (unless you park up to 2 pets before the reset).
4. You gain a permanent Luck multiplier that boosts every future cash/second.
5. Your cash gains are multiplied by (1 + R) where R is your new tier.

The permanent Luck multiplier stacks with the 2x/4x Permanent Luck gamepasses (see Gamepasses).

The published R1–R8 ladder

Sportskeeda and ProGameGuades publish an 11-tier ladder (R0 → R8) with a 5× cash pattern. R1 is the only developer-verified tier. R2 is community-reported. R3–R8 follow the published 5× ladder pattern and are marked INFERRED in the calculator’s JSON config:

The “5×” pattern means each tier requires 5× the previous tier’s cash threshold. R2 → R3 = $190K × 5 = $950K, and so on.

The Rebirth ROI Calculator

The Rebirth ROI Calculator is a pure-math optimizer that compares NPV at your current tier versus NPV at your target tier. It loads the R1–R8 ladder from src/data/config/rebirth-ladder.json and runs the calculation entirely in your browser.

Inputs:

• Current cash on hand.
• Placed roster (up to 30 pets, each with name, rarity, and $/s).
• Current Rebirth tier (R0–R8).
• Target Rebirth tier (R1–R8).
• Planning horizon in days.
• Offline efficiency (0–1).
• Event multiplier.
• Rolling drag factor (0–0.5).
• Park count (0–roster length).
• Strategy (standard / alt-account / private-server).

Outputs:

• NPV at current tier, NPV at target tier, NPV delta, 10% premium threshold.
• Recovery hours (how long your current cash flow takes to cover the gap to the target tier).
• 3-tier projection (R+1, R+2, R+3 from current tier).
• Strategy comparison row (standard vs alt-account vs private-server).
• Park/sell lists.
• Missing pets for the next tier.
• Engine warnings (including INFERRED-tier warnings).

The four recommendation outcomes

The calculator returns one of four recommendations:

• REBIRTH NOW — NPV delta beats the 10% premium threshold AND recovery takes less than 48 hours.
• WAIT ONE TIER — conditions are mixed or you don’t have the required pets for the next tier.
• DO NOT REBIRTH — NPV delta is below threshold and recovery exceeds your planning horizon.
• BUILD A ROSTER FIRST — your roster produces no cash or has fewer than 2 pets.

The 3-tier projection

The projection table shows what happens if you push R+1, R+2, R+3 from your current tier. Each row carries:

• The cash threshold at that tier.
• The days-to-afford under your current strategy and current roster.
• The permanent Luck multiplier at that tier.
• A label marking whether the tier is verified or INFERRED.

Use this to plan the climb instead of guessing. If the R+3 row shows 60+ days-to-afford, you’re better off optimizing the current roster than racing to R+3.

Strategy comparison

The same engine, three different efficiency multipliers:

• Standard (1.00×) — your usual public-server play.
• Alt-account (0.85×) — accounts for a second account that splits your active time.
• Private server (1.10×) — assumes a VIP server where you can lock your base (subject to the Private Server Risk caveats).

The table shows the NPV under each strategy on the same horizon. Use it to decide whether a private server subscription is worth the R$ cost.

What to park, what to sell

The park list keeps your top N pets by cash/second. The default park count is 2 (the typical “park two, sell the rest” pattern reported by Sportskeeda). The sell list shows what you’d discard.

If you don’t have a required pet for the next tier, the calculator surfaces it as a missing-pets card. Roll the Egg Mystery hologram until you have the right pair before attempting the Rebirth.

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/
• AllThings.How beginner guide: https://allthings.how/build-a-base-and-steal-beginner-s-guide-to-pets-rebirth-an

What to read next

• AFK Income and Cap — model the offline cash half of the post-Rebirth economy.
• Pet List — every named pet by rarity tier.
• Gamepasses — how the Permanent Luck gamepasses stack with the Rebirth multiplier.