aclaybrook / danddsimulator

Dungeons and Dragons Damage Simulator

Live here: https://d-and-d-damage-simulator-745953dd5908.herokuapp.com/

For the D and D Theory Craftors of the World

• Simulates many thousand turns of combat to find distributions of damage for a given character
• Compare D&D characters at once for the theory crafters of the world, i.e.:
  • A Barbarian with Reckless Attacks with Advantage
  • A Fighter With the two Great Weapon Master Feat
• Not sure which Feat to take for optimal DPS? Well why not simulate them all and find out?

References/Motivation

• https://www.youtube.com/@DnDDeepDive
• https://www.reddit.com/r/BG3Builds/comments/157p0cl/the_math_of_critical_hits_in_dd_5e_is_critfishing/?onetap_auto=true
• https://statmodeling.stat.columbia.edu/2014/07/12/dnd-5e-advantage-disadvantage-probability/
• https://forums.giantitp.com/showthread.php?582779-Comprehensive-DPR-Calculator-%28v2-0%29
• https://anydice.com/program/22f8c

How to Install and Run Locally

• Download or git clone the repo from: https://github.com/AClaybrook/DAndDSimulator
• Linux terminal install instructions:
  • Install the python and requirements
    • Install python3.11+ if needed from https://www.python.org/downloads/
    • Install pipenv if needed pip install pipenv
    • pipenv install --ignore-pipfile
  • Activate the virtual environment
    • pipenv shell
  • Launch the App on localhost 8050:
    • python app.py
    • Or run app.py from VsCode

Technical Notes/Features:

Completed Features:

• UI: Character, Enemy, Simulator, and Tables
• Collapsable nav/sidebar
• Import and Export of characters via json
• Simulate Combat from UI values
• 4 different simulation types and corresponding plots:
  • Damage Per Round
  • Damage Per Attack
  • Damage Per Round vs Armor Class
  • Damage Per Attack vs Armor Class
• Export Damage Results to csv
• Implement easy callbacks in javascript
• Reduce memory of dataframes
• Random Seed toggle for random vs repeatable results

In Works

• UI design
  • Update attacks based on selected type
• Double check values are identical when reading elements
  • characters and attacks in UI get translated to python and back the same way
• Performance gains in callbacks

TODO

• Import Character Presets
• Design of Experiments (vary a specified parameter)
• "Leaderboard"
• Tips for UI
• Validate numerical sims and implement tests

Backlog

• 5e vs BG3 ruleset
  • Currently all calculations are implemented using the BG3 ruleset
• Expendable resources/damage over time
  • Can currently be simulated as a different character
• Simulate turns to kill a monster
• Ability checks
• Monsters presets
• Saving/uploading enemys
• Variable Color Theme
• Concept of # of encounters per short/long rest for resources
• Extract "insights", i.e. when to turn on/off GWM/Sharpshooter
  • Have to manually look at graphs/tables currently
• Damage Source, to see impact of various combinations, i.e. damage gain from bless
  • Alternatively could just implement diffing characters
• Multiple Enemys
• Summary Stats Section
• Better app logging
• Preview character bonuses to attack

Current Assumptions/Limitations

• Classes and Races are not fully implemented, just the main damaging perks
• Assume resources are unlimited (i.e. not tracking spell slots)
• No multitarget, single target only
• Enemys do not fight back/ not considering back and forth combat. So a character with 10 hp and 10 ac is just as good at damage as a character with 100 hp and 20 ac. Only enemy defensive stats matter
• Do not consider turn order/initive
• 1 character at a time, no party mode
• 1 Enemy at a time
• Focused on damage, therefore actions that do not involve damage as not implemented
• Validation of build feasability is not done. Garbage in/ garbage out
  • Only some basic checks like GWM only with twohanded weapons
• Adjusting rolls needed for critial hits (Crit on) needs to be applied manually, i.e. a Fighter taking the Champion subclass, spell sniper feat need to be accounted for by manually reducing the Character Crit on field
• no status effects, stunned, restrained etc

Callback Implementation Quirks:

• Copy callback and others get called unintentionally when a character is deleted, because the Inputs techically change
  • Solution is to check time of the last clicked button and skip if copy wasn't clicked last
• Can not use MATCH for an Inuput when an Output doesn't have a MATCH, thus have to reach in ALL Inputs

Build ideas

• Bladesinger
• Ice Sorcerer, prone
• Fire sorceror
• Gloomstalker, assasin
• Wardomain cleric,
• Life domain cleric, healing extreme
• Barbarian cleave (bleed build)
• Bard crossbow arcane acuity
• Pure Fighter