Once finished, this tool will allow you to get a rough estimate of how difficult an encounter will be, by simulating battles a high number of times, using quantifiable abilites (attack rolls, abilities that grant advantage, etc.)
Goal of this tool is to help Dungeon Masters (or DMs) estimate the difficulty of battle scenarios by estimating how many players survive (and maybe by how much). The DM then uses these estimates and knowledge about the players' and creatures' behaviours and abilities to estimate how difficult the battle scenario is for the players.
To reach that goal, battles are simulated several times (order of magnitude 10^4), and the basic types of actions are considered:
Battle aspects like movement, terrain, etc. are not considered. Nor are more complex abilities like a bard's "Crown of Madness". Therefore this is no real simulator, but more of an estimator (maybe we should change the name *cough*).
Can be found in goals.md (what should go in, what should come out?) and design.md (who should probably hold information on whom?).
It's our own experience that it's hard to estimate the difficulty level of a DND5E battle, even with Wizards of the Coast's challenge rating system, which turns out to greatly overestimate the difficulty. "Deadly" battles frequently turned out to be way too easy for our players.