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d20 Attack Calculator Screenshot 0
d20 Attack Calculator Screenshot 1
d20 Attack Calculator Screenshot 2
d20 Attack Calculator Screenshot 3

About d20 Attack Calculator

d20 Attack Calculator is a powerful combat calculator, optimization tool, and dice roller for d20 RPG systems such as Pathfinder RPG or D&D 3.0 / 3.5 / 5th Edition. Use this program to roll dice for your complex attack routines and evaluate your character build from visual graphs and dice roll statistics.

* Attack calculator and dice roller / calculator
* Plot key statistics for your dice rolls:
- Expected (average) damages
- Hit chances
- Dice roll distribution and averages
* Analyze your DPR (damage-per-round) and appropriate challenge rating
* History data for your d20 attack rolls

The DPR analysis can be used to tell you how long it takes you to solo a monster of a given CR (or AC), on average, providing players a rough measuring tool to estimate their power level.

See more information on how the DPR calculations are done and a tutorial on "how to determine when to use Power Attack" at:

If you would like to test the program, check out the free Lite version. This full version includes all the features of the Lite version an in addition:

* Unlimited saving and loading of attack routines and plotted graphs
* Hit chance graphs for attacks
* Multiple buffs/debuffs to attacks
* Export plotted data to other programs
* More statistics and graph data from your past d20 rolls

What's New?

Ver. 1.9: Improved dice roller: compute powers, multiplications, divisions, and roll High/Low rolls. E.g.: 4d6H3 - roll 4d6 and keep the 3 highest dice. 2d20L - roll 2d20 and keep the lower dice.

Ver. 1.8: Support for 5th Edition rules and Advantage/Disadvantage buffs. Roll distributions can now be evaluated in the Stats dialog to get the chance of scoring more/less than a given dice roll. Customization: "Use Target AC" option can now be disabled from the Settings. Added an option to show chances for "all attacks miss" curve. Minor bug fixes. I'm still quite new to the 5th ed. rules, so all feedback is very welcome!

Ver. 1.7: Added a generic dice roller, which can also show stats such as averages and result distribution for the roll. Minor bug fixes.

Ver. 1.6: Added Quick Buffs to attacks for faster bonus controlling. The history of the past d20 rolls can now be monitored from the Data and Settings page.

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There are lots of fruits in granny's fruit garden. Pick and sort...

The ONLY legit attack/damage dice roller. This really streamlines play. I paid for it right away. I look forward to future development. I would love too see an option for the 4th edition rule of max damage o...
James Robicheau
I just bought this for my totemist and it has already saved me like 2 minutes per turn. Its amazing. Only thing I would enjoy being different would be the roll result page having a scroll feature or expandin...
Alex King
Wonderful app for handling all the attacks of a 2 weapon fighter. Lots of flexibility for adjusting the attacks and damage per swing. Would love the option to save different attack sets for simpler access!
Stephen Turner
This is a great app for any d20 players, I've used it as a player and gm. I have had issues finding a place to delete saved attacks.
Gideon von Bose
Great app. Would be awesome if there was an option to calculate with the elven accuracy feat.
josh whitlock
I've used it for graphing damage results for years. It's always worked better than anything else I've found.
Lily Depot