Probably Stolen Theft & Insurance: Break-in Odds, Alarm and Premiums
Each uninsured night has a 33% base theft chance plus 5% per consecutive uninsured night, so it reaches 100% after 14 nights. A thief takes one random eligible item. Insurance (from Day 4) returns it next morning and costs 3 + 1 Credit per 400 of total assets per night on Normal.
On this page
Theft chance each night
Example: your first uninsured night is 33 + 5 = 38%. By the 14th uninsured night in a row the chance is 100%. An insured night resets N to 0.
| Factor | Change |
|---|---|
| Base chance | 33% |
| “Targeted” in the Lower Levels | Base becomes 66% |
| Each consecutive uninsured night (N) | +5 × N, counting tonight |
| Active security protection | −16 |
| Result | Clamped to 0–100% |
Ordinary theft is skipped entirely before insurance is unlocked, while Cartel protection is active, or with the Alert perk.
What a thief takes
A thief picks one eligible item at random — not necessarily the most valuable one. Documents, machines, container bodies, items worth 0, items in a Smuggler’s Bay and items tagged important or locked are skipped.
Protecting a container does not protect what is inside it. Check the night log first each morning, then compare it with your inventory.
Alarm System
| Rule | Detail |
|---|---|
| Power | Needs its own powered battery and must be switched on. Paying for the Power Service alone is not enough. |
| Displayed protection | 50 + module performance bonus |
| Real interception chance | Displayed value +1 point (50 shown = 51%; 99 shown = 100%) |
| Modules | Efficiency changes power use; performance raises protection; quality does nothing |
| Scope | Only ordinary night theft. The under-counter security button is a separate thing. |
Worked example: first uninsured night (38%) with a 50 alarm (51% stop) leaves a 38% × 49% ≈ 18.6% chance of losing an item.
What insurance covers
| Loss | Covered? |
|---|---|
| Items stolen during an insured night | Yes — returned next morning |
| Inspection seizures | No |
| Trash Can emptying | No |
| Production losses | No |
| Black Market “refusal to insure” | Insurance becomes unavailable |
Is insurance worth it?
Early on, a 4–10 Credit premium (less after the rebate) is cheap compared with losing one valuable item. Insuring also resets the escalating uninsured-night counter.
Skipping a night or two is a reasonable gamble when your shop holds little. Never let the streak run long: after a week uninsured the chance is above 65% before the alarm.
This is planning advice based on the formulas above, not a measured result.
Common questions
Why do items get stolen at night in Probably Stolen?
Every uninsured night rolls a theft check: 33% base plus 5% per consecutive uninsured night. An Alarm System can stop the thief.
How much does insurance cost?
On Normal: 3 Credits plus 1 per 400 Credits of total assets, per night. It doubles if you are targeted, and is ×2 on Hard and ×3 on Challenge.
Does the thief take the most expensive item?
No. It picks one eligible item at random. Documents, machines and locked or important items are excluded.
Sources & version notes
Community game-data research (static, not in-game tested). Sources reviewed November 1, 2026. This guide does not claim an independent in-game test.
- Nico Wiki: theft and insurance
Theft rate formula, alarm interception and item selection.
- Nico Wiki: insurance service
Premium formula and coverage.
- Nico Wiki: contacts network upgrades
Nightly service rebates by difficulty.