DPR Simulator

The first concept to understand is the character. A character is what it sounds like - a table top gaming character that does damage, and you want to know how much damage to expect.

Characters can be created either from scratch or by loading a pre-existing example. The data you create for each character is very specific, so the examples are primarily there for demonstration purposes. In most cases, you'll want to start from scratch.

Once you've created a character and loaded their damage sources and links (discussed in the following pages), you can navigate to the Damage Report tab to see the results of a damage simulation. 10,000 turns are simulated for each armor class starting at 5 and ending at 25. The average damage of your character at each armor class is then plotted on a graph for visualization purposes, and the raw data is available in a table below the graph. Every charater you have created at time of clicking the Damage Report tab will be simulated and plotted together.

Important: only one character can be edited at a time. You must denote a character as the "Active Character" on the Manage Characters tab in order to edit the damage sources and links for that character. When you create your first character, it will automatically be marked as the active character.

The second concept to understand is the damage source. A damage source is any instance of your character applying damage on a given turn. Each weapon attack is one damage source. Each bolt from Eldritch Blast is one damage source. The full 8d6 damage from a fireball is one damage source, and it is best to configure the 4d6 damage on a successful save as its own damage source as well. Damage sources may require attack rolls, or they may automatically apply when triggered (triggering damage sources is discussed on the links page of this guide). Damage sources which don't require attack rolls may impact multiple targets at once. The settings for a damage source can be grouped into three categories: damage, attack roll, and multitarget. Next, I will discuss each of those categories.

Damage settings for a damage source define how much damage the damage source does:

Damage die size: This is the size of the damage dice rolled when you roll damage for this damage source. You can also select Flat here to indicate that no damage dice are rolled and rather a single number is applied (for example, Storm Herald barbarians at level 5 can automatically deal a flat 3 damage on their turn as a bonus action).
Amount of dice/Flat amount: The label for this input will change depending on if you have selected a dice size or "Flat" in the Damage die size input. If you have selected a dice size, this is the amount of dice rolled for that damage source (e.g.: a long sword is 1 dice, a fireball is 8, etc.). If you selected a "Flat" amount, then this is the flat amount (e.g.: the 3 points of damage used in the Barbarian example above).
Total damage modifier: This is the number you add to the damage roll. For a Strength-based weapon attack, it is typically your Strength modifier. If you have a magic weapon that boosts your damage by a flat amount, then that would be included here as well. (e.g.: a fighter with 18 Strength and a +1 magic great sword would input a +5 here, resulting from 4 (from Strength) plus 1 (from the magic weapon).
This damage can crit: Check this checkbox if the damage is boosted when the damage source is applying to a critical hit (e.g.: the hex spell or divine smite or a weapon attack or virtually anything that involves rolling extra damage dice when a critical hit occurs).
Extra dice rolled on crit: This input is only visible if you indicated that the damage can crit. It is simply the amount of extra dice rolled on a crit. For example, a level 5 rogue does 3d6 sneak attack damage. On a crit, they do an additional 3d6 critical damage, so 3 would be input here. As another example, a 9th level half-orc barbarian rolls two extra dice when landing a critical hit on top of the normal one extra dice, so 3 would be input there as well.
Reroll low damage numbers: This checkbox indicates that your character is allowed to reroll damage if the roll is below a certain amount. For example, Fighters with the Great Weapon Fighting fighting style can reroll 1s or 2s, but they must keep the new roll.
Reroll damage die (and keep the result) if less than: This input is only visible if "Reroll low damage numbers" is checked, and it is the threshold below which dice are rolled. For the Fighter with Great Weapon Fighting example above, it should be set to 2.
Rolling damage with advantage: This input indicates that you get to roll your damage for this damage source twice, and keep the higher total.
Roll advantage first/reroll low numbers first: If you indicated that this damage source has both damage advantage and can reroll low numbers, this toggle indicates which is applied first.

Attack roll settings are only visible if you check the box indicating that this damage source requires an attack roll. Attack roll settings for a damage source define the terms of hit accuracy and critical hits and the like:

Attack bonus: This is the total modifier you add to your D20 roll when calculating damage. It is typically your proficiency bonus plus your modifier plus any bonus from your weapon. For example, a fighter with 18 Strength and a +1 Great Sword at level 5 would have 4 (from Strength) plus 3 (from proficiency bonus) plus 1 (from magic weapon) for a total attack bonus of +8.
Critical hit threshold: This is the number at which you crit. It is typically 20, but sometimes less; for example, level 3 Champion Fighters crit on a 19, so they would put a 19 here.
With advantage/with disadvantage: Only one of these can be selected at a time. These boxes indicate if multiple D20s are rolled and you take the higher (in the case of advantage) or the lower (in the case of disadvantage).
Amount of extra d20s on advantage/disadvantage: This is the amount of additional D20s you roll when your attack roll is affected by advantage or disadvantage. This is typically 1, but features such as the Elven Accuracy feat bump it up to 2.
Extra dice on attack roll: This checkbox indicates that you get to roll additional dice when you miss in an attempt to turn the miss into a hit. For example, Battle Master Fighters with Precision Attack can add their superiority die to the attack roll.
Extra dice size: This dropdown is only visible if you selected "Extra dice on attack roll" and it indicates the size of that extra dice. For example, the level 3 Battle Master Fighter has a D8 superiority die it can use.
Use extra dice if miss by less than: This input is also only visible if you selected "Extra dice on attack roll", and it is the threshold below which the extra dice are rolled. For example, if you are conservative with your Superiority Dice and Precision Attack, then you might put a low number here, indicating that you only use them if you barely miss.

Multi target settings are only visible if you check the box indicating that this damage source can affect multiple targets. Each of the multi target settings indicates the percentage of time you think a target will be available. This is best explained through examples:

Melee fighters: These characters are in the thick of the fight. Their area-of-effect abilities should be expected to always include one enemy, often two, and sometimes three. However, unless surrounded, it's unlikely they consistently have four or five enemies in their range. This could be indicated in the tool by selecting, for example, 100%, 50%, 25%, 0%, and 0%, all in that order.
A wizard casting fireball at a horde of goblins: A wizard with a horde of goblins running at them has a high chance of having many goblins in their fireball. However, some will pass the save. For this character, it is best to configure two damage sources: one that does 8d6 damage ( to represent the goblins that fail their save) and one that does 4d6 damage (to represent the goblins that pass their save). In either case, it's likely that the target availability is high. This could be indicated in the tool by selecting, for example, 100%, 100%, 75%, 50, 25%, in that order, for the failed save damage source. For the passed save damage source, the numbers would be similar, but perhaps a bit lower, because the wizard not only needs the goblins in the radius of the fireball, but they must also fail their save.
A cleric casting spirit guardians and running around the battlefield: Like the fighter above, this character is purposefully putting themselves in the thick of the fight because their area of effect damage is centered on them. They likely have a similar target availability as the fighter. However, like the wizard, a save can be succeeded on to result in half damage.

The final concept to understand is the link. It is sometimes the case that one damage source relies upon another damage source either hitting or critting. For example, you can't divine smite on a miss. You need an attack to hit, and then you add the divine smite to that hit. Another example is sneak attack, which requires a hit to occur. A third example is the bonus action attack from Great Weapon Master, which can be enabled by landing a critical hit during the attack action.

Links are defined by four things:

A source with a dependency. This is the damage source which must either hit or crit in order to enable another damage source to occur. For example, an attack must land in order to perform divine smite. The source with the dependency is then the attack itself.
A dependent source. This is the damage source which relies upon the first damage source. In our divine smite example, this would be the divine smite damage source.
The type of dependency This indicates if the triggering damage source must hit or crit in order to trigger the dependent damage source.
Whether or not critical hits propogate through the link. This setting means that if you score a critical hit with the primary source, then the dependent source is a critical hit as well. Continuing with the divine smite example, the link between the attack and the divine smite does propogate critical hits. If you crit with your attack roll, you don't just roll double damage on the attack roll and normal damage on the smite - you roll double damage on both. However, something like the Genie Warlock's feature Genie's Wrath cannot crit, as it is a flat amount of damage, and so you would not select that critical hits propogate through the link from successful hit to Genie's Wrath.

Important: if multiple links point towards the same dependent source, then only one of those links must be satisfied to trigger the dependent source. For example, the Great Weapon Master barbarian's bonus action attack can be triggered by a critical hit with either one of their attacks in their attack action, so one link would be set up from each attack damage source to the bonus action attack damage source, and if either link is satisfied (meaning a crit was scored), then the bonus action attack damage source would apply that round.

Select an example to learn more about it:

The Rogue

The rogue in this example is dual wielding daggers, and, like all rogues, deals sneak attack damage. This can be configured in the tool using three damage sources and two links, which I describe below.

The first damage source is the main hand dagger. This is used to take the attack action, requiring an attack roll, which is indicated in the damage source creation menu. As such, it does 1D4 damage, and we're allowed to add our Dexterity modifier to the damage. For a level 3 rogue, it is reasonable to assume a 16 Dexterity, which equates to a Dexterity modifier of +3. It is possible to crit with a dagger attack, and an extra 1D4 is rolled when this occurs, so both of these things are indicated in the damage source. Finally, in this example, I assume the first attack has advantage, because I'm assuming I'm hidden to start my turn. Attacking reveals you, however, so the advantage does not apply to the next attack discussed below.

The second damage source is identical to the first, but with a damage modifier of +0 instead of +3. This is because adding your damage modifier to your bonus action attack when dual wielding requires feats, and I am not assuming that this rogue has those feats.

The third damage source is sneak attack. At level 3, this is 2d6 extra damage. If it is applied on a hit that happened to be a critical hit, it becomes 4d6 damage. This is indicated in the tool by specifying the damage source can crit, and it does 2 extra damage dice when it crits. No additional attack roll is required for this - it simply is added on to an attack that has already hit.

Both of the links indicate that sneak attack is conditional upon a hit. The first link causes sneak attack to be applied if the main hand attack hits, and the second link causes sneak attack to be applied if the second attack hits. As always, these links are combined in an OR fashion - if either condition is satisfied, sneak is applied. Thus, sneak is only applied once per turn, even if you hit twice. Sneak attack damage doubles form 2d6 to 4d6 if it's applied to an attack that crits. This is configured during damage source creation by selecting that the damage source can crit, and during link creation by indicating that crits propogate to Sneak from the triggering attack.

The Warlock

The warlock in this example is casting Eldritch Blast. They are a genie warlock, so they get to add their proficiency bonus to one hit once per round. They are also concentrating on Hex, enabling yet another 1D6 damage to one hit once per round. A 20 in Charisma is assumed for this particular higher-level character. This character requires five damage sources, two of which are contingent upon the other three, resulting in a total of six links being necessary as well.

The first three damage sources are configured identically. They are standard attack-roll-required damage sources, without advantage, and with the ability to crit. Each is a D10 of damage from Eldritch Blast, with an additional 5 points of damage resulting from the Agonizing Blast invocation. Note that if this were a spell such as Firebolt, which also does 3D10 damage in total, then there would only be one damage source, as it is an all-or-nothing spell. Eldritch Blast is unique in that each D10 of damage comes from its own attack roll, so three damage sources are required to represent it.

The next damage source, Genie's Wrath, is a flat bonus of damage to one attack roll once per turn, in an amount equal to the proficiency bonus of the warlock, which is +4 at level 11. This damage cannot crit, so the box for that is left unchecked here.

The final damage source, Hex, is similar to Genie's Wrath. It applies once per turn on one successful hit. However, it is a D6 of damage, and it can crit.

All six links are very similar. The first three indicate that if any one Eldritch Blast bolt hits, then the Genie's Wrath bonus should be applied that round. The remaining links indicate the same, but for Hex instead of Genie's Wrath. Note that the Hex link does specify that crits on the triggering damage source do apply to the Hex damage source. This means that if you crit and apply Hex on the same attack, you roll 2D6 instead of 1D6 when determining the Hex damage.

The Paladin

The paladin in this example is wielding a long sword and a shield, which means his weapon attacks deal 1D8 damage. They are assumed to have a 16 Strength because they have focused on Charisma. They have done so in part because they are heavy users of Spirit Guardians as well. Their plan of attack: cast and maintain Spirit Guardians on the battlefield while slashing with the long sword, using divine smite only on critical hits. Furthermore, as a level 11 paladin, they will be applying an extra 1D8 to all melee hits, thanks to the Improved Divine Smite feature.

The first two damage sources are identical: 1D8 long sword strikes with the normal critical hit range and extra dice. There is a +7 attack modifier from the +4 proficiency bonus and +3 in Strength. The damage modifier is then +3 from Strength as well.

The second two damage sources are also identical. They are divine smites cast at second level, as this paladin is saving their 3rd level slots for Spirit Guardians. There is no attack roll required for divine smite, and at 2nd level it does 3d8 damage, so 3 dice are input as the amount to roll. Furthermore, smite can be enhanced by a critical hit, so this is denoted in the tool, alongside 3 extra dice on crit. It is necessary to create one divine smite damage source for each attack because one can occur on each attack. If we only created one Divine Smite damage source, then it would only apply a maximum of one time per round.

The third two damage sources are identical as well. These are from the level 11 paladin feature Improved Divine Smite. These also do not require an attack roll, they simply apply if conditions are met. These conditions are outlined in the links page. These sources also benefit from crits, so this is specified as well. Two Improved Divine Smite damage sources are needed for the same reason two Divine Smite damage sources were required.

The final two damage sources are Spirit Guardians. These damage sources do not require an attack roll, and can affect multiple targets, so this is specified in the damage source creator for both. Spirit guardians does 3d6 damage to targets that fail their save, and half that to targets that succeed. As a result, one damage source is configured to reflect enemies failing their save, and a second is created to reflect enemies passing their save. In each one, we assume similar target availability - one target is available half the time, a second target is available a quarter of the time, and a third target is available 10% of the time. This effectively means that as a melee Paladin, we expect that we will typically be in the thick of the fight, with at least one enemy very nearby, and sometimes up to three.

The first two links reflect the application of Divine Smite only on critical hits. Each one is linked to a different attack for reasons outlined above. Critical hits are indicated to propogate through this link, ensuring that applying a divine smite to a critical hit results in 6D8 damage instead of 3D8.

The second two links are similar. They reflect the applciation of Improved Divin Smite, but on every single hit. Again, critical hits are indicated to propogate through this link.

This tool performs best on desktop.

Damage settings

Attack settings