Configure Your Rolls
Choose options, then roll securely using the server.
Example Data Table
| Setting | Example value | What it does |
|---|---|---|
| Number of rolls | 5 | Creates five independent d10 results. |
| Modifier | +2 | Adds two points to every kept natural roll. |
| Mode | Advantage | Rolls two d10s and keeps the higher result. |
| Target | 9 | Final results of 9 or greater succeed. |
| Reroll 1s | Enabled | Rerolls an initial natural 1 once per candidate. |
Formula Used
Normal mode keeps one d10. Advantage keeps the higher of two d10 results. Disadvantage keeps the lower result. When a target is supplied, a roll succeeds when the final result is greater than or equal to the target.
The displayed target chance is exact. The calculator builds the natural-result probability distribution, applies the selected mode, then adds every probability that reaches the target after the modifier.
How to Use This Calculator
- Enter the amount of d10 rolls you need.
- Add any bonus or penalty in the modifier field.
- Select normal, advantage, or disadvantage mode.
- Enter a target number when you need success checks.
- Enable optional rerolls, labels, sorting, or timestamps.
- Select Roll 1d10 to view outcomes above the form.
- Download CSV or PDF after reviewing the roll table.
Understanding 1d10 Rolls
A 1d10 roll produces one whole number from 1 through 10. Each face has an equal chance in normal mode. This makes a d10 useful for game systems, lessons, simulations, and scoring rules.
The modifier changes the final value, not the natural face. A +3 modifier turns a natural 6 into a final 9. A negative modifier reduces the final result. Keeping both values visible helps players audit each step.
Targets convert a random result into a pass or miss check. For example, a target of 8 succeeds on final values of 8 or higher. The calculator counts successful results and shows the exact single-roll chance for your settings.
Using Advantage and Disadvantage
Advantage rolls two d10s and keeps the higher result. It raises the chance of higher outcomes. Disadvantage rolls two d10s and keeps the lower result. It raises the chance of lower outcomes.
These options are helpful when game rules reward preparation or impose difficult conditions. The candidate-roll column shows both dice. You can see why a particular natural result was kept before the modifier was applied.
Rerolling natural 1s once changes the distribution. Most faces become slightly more common, while a final natural 1 becomes uncommon. The exact target chance automatically accounts for this rule.
Reading a Batch of Results
Multiple rolls are useful for encounters, damage tables, classroom demonstrations, or repeated trials. The summary cards show the count, total, average, minimum, and maximum. These values make patterns easier to inspect.
Critical labels identify natural 1s and natural 10s. They remain tied to the kept natural result, even when a modifier changes the final number. This prevents a high bonus from hiding the original die face.
Sorting is optional. Keep the default order when sequence matters. Sort high to low when you want fast comparison. Exporting gives you a reusable record for notes, reports, or game-session archives.
Fair Results and Clear Records
The roll engine uses PHP’s cryptographically secure random integer generator. It does not use predictable browser math. This is useful when users want reliable random values during a shared session.
CSV opens in spreadsheets. PDF creates a compact session report. Both exports include the candidate dice, kept natural result, modifier, final value, target, and outcome. Review the table before saving your session.
Frequently Asked Questions
What does 1d10 mean?
It means roll one ten-sided die. The normal result is an integer from 1 to 10, with each face equally likely before optional rules are applied.
Can I roll more than one d10?
Yes. Set the number of rolls from 1 to 100. The calculator records each result, plus batch totals, average, range, success count, and critical labels.
How does the modifier work?
The modifier is added to the kept natural roll. For example, a natural 7 with a -2 modifier gives a final result of 5.
What is advantage in this tool?
Advantage rolls two d10 candidates and keeps the higher one. It improves your chances of reaching higher targets compared with normal rolling.
What is disadvantage in this tool?
Disadvantage rolls two d10 candidates and keeps the lower one. It makes high outcomes less likely and can model difficult conditions.
How are target chances calculated?
The calculator evaluates every possible kept natural result under your mode and reroll rules. It adds probabilities for results that meet the target after the modifier.
Does rerolling 1s guarantee no natural 1?
No. A rerolled 1 can still become another 1. The option only gives a first natural 1 one additional attempt.
Are natural 1s and natural 10s affected by modifiers?
The labels use the kept natural die value. A modifier changes the final score, but it does not change whether the kept face was a 1 or 10.
Can I leave the target empty?
Yes. The tool then displays roll results and summary statistics without calling any result a success or miss.
What is included in the CSV export?
The CSV includes the roll number, candidate rolls, kept natural result, modifier, final result, target, and outcome. It opens in common spreadsheet programs.
Is the random roll secure?
Yes. The server uses PHP’s random_int function, which is designed for cryptographically secure random integer generation when the server environment supports it.