Configure Your Roll
Choose the dice rules, then generate a transparent batch of D3 outcomes.
Example Data Table
| D3 Dice | Modifier | Target | Rules | Sample Final |
|---|---|---|---|---|
| 1 | +0 | 2 | Standard roll | 2 |
| 3 | +1 | 8 | Standard roll | 9 |
| 4 | +0 | 9 | Drop lowest | 10 |
| 2 | -1 | 4 | Reroll ones once | 4 |
| 2 | +0 | 5 | Keep higher attempt | 6 |
Formula Used
Base Total = sum of kept active D3 values
Final Total = Base Total + Flat Modifier
Success = Final Total ≥ Target Total
A standard D3 has a one-in-three chance for each face. Its expected value is 2. With a reroll of ones once, one die has an expected value of 7/3, or about 2.33. Custom high, low, and drop rules are evaluated through the displayed rolls and optional simulation.
How to Use This Calculator
- Enter how many three-sided dice belong in each roll.
- Set a batch size when you need several independent results.
- Add a modifier and optional target total for a success test.
- Choose rerolls, drop-lowest, or a high and low roll style.
- Press the roll button and read the result panel above the form.
- Download CSV or PDF after a result appears.
Understanding D3 Rolls
A D3 is a three-sided random result generator. It produces one, two, or three. Many tabletop games use it for compact ranges. It can also model simple choices. This calculator handles one roll or a complete batch. It keeps every outcome visible. That makes quick checks easier. It also helps players understand how rules change results.
A standard D3 total is the sum of every active die. Rolling four dice can create totals from four through twelve. A flat modifier changes the final total after addition. Positive modifiers improve the score. Negative modifiers reduce it. The calculator displays both totals. You can therefore check the math without guessing.
A target total turns a random roll into a success test. Enter the minimum score needed. Each generated row will show success or failure. The batch success rate describes only the rolls you just made. The estimated chance uses many additional simulated rolls. It gives a useful probability estimate. Larger simulations usually create steadier estimates.
Rerolling ones changes the dice process. When enabled, an initial one is rolled once again. The second result becomes the active face. A second one remains a one. This rule raises the average result. It does not remove every low outcome. The raw details show each changed die with an arrow.
Dropping the lowest die removes one active value before totals are calculated. This option works only when two or more dice are rolled. It generally raises the expected total. The display lists kept values clearly. It also shows the dropped value. Combine it with rerolls when your game rules allow both effects.
The high and low roll styles create two complete attempts. High style keeps the better total. Low style keeps the worse total. These modes are useful for advantage and disadvantage variants. The selected attempt is shown in the results table. The alternate total remains visible for comparison. Modifiers apply after the selected base total.
Use the frequency counts to see which faces appeared. Compare the observed average with the expected range. Exporting CSV keeps a record for a campaign, lesson, or test. The PDF option creates a readable snapshot. Reset the form when starting a new setup. Random tools are helpful, but transparent rules make every roll easier to trust for every player today.
Frequently Asked Questions
What is a D3?
A D3 is a three-outcome die or randomizer. It returns one, two, or three with equal likelihood in a standard roll.
Can I roll more than one D3?
Yes. Enter the number of dice per roll. The calculator adds all active dice, then applies your flat modifier.
What does the flat modifier do?
The modifier is added after the kept dice are summed. Use positive numbers for bonuses and negative numbers for penalties.
How does a target total work?
Enter the minimum final score needed. A roll succeeds when its final total is equal to or greater than the target.
What does reroll ones once mean?
Each initial result of one is rolled one additional time. The second result becomes active, even when it is another one.
When does drop lowest apply?
It applies only when at least two dice are rolled. One lowest active die is removed before the base total is calculated.
What are high and low roll styles?
They make two complete attempts using the same rules. High keeps the better base total. Low keeps the worse base total.
Is the estimated chance exact?
No. It is a simulation estimate based on the number of trials you choose. More trials normally reduce random variation.
Why can a rerolled one still show one?
The reroll is random and can produce any D3 face. The rule rerolls once; it does not repeat until a higher result appears.
What information is included in the CSV file?
The CSV includes the visible summary metrics and every row in the results table. It works well for spreadsheets and records.
Can I print or save the output as PDF?
Yes. Select Download PDF after results appear. The exported file includes the configuration summary, metrics, and detailed roll table.