One can easily calculate DPR given a specific build (knowing proficiency bonus, ability scores, other relevant factors) and the AC of opponents, leading to spreadsheets with a matrix of customizable parameters. But what if one wants to calculate an average DPR considering typical build choices against typical CR encounters? As character attack bonuses go up, so do opponent ACs, so is there commonly used rule of thumb for an average chance to hit?
For example, the following sources use chances of hitting that are apparently intended to be applied across tiers:
- 50%: What is the expected DPR of an animate object spell cast on daggers? ("11+ on the d20 is required to hit")
- 60%: https://www.youtube.com/watch?v=zg0bAl1WPGQ&t=9m5s ("This warlock's going to have about 60% chance to hit. And, honestly, that ends up being pretty close to the average.")
- 65%: https://www.enworld.org/threads/guide-my-word-is-my-sword-the-paladin-guide.474035/ (used several places throughout the guide)
- 65%: Weapon attacks compared with damaging cantrips? based on:
- ASI goes into attack ability
- Attacks will be made against average AC of a CR = character level, as seen on DMG274
Is there a widely agreed upon likelihood of hitting in a generic, CR-appropriate encounter (e.g. 50%, 65%, etc.)? Is there one that is consistent across levels or tiers? How is this value arrived at? (E.g. likely character attack bonuses, AC of CR-appropriate opponents…)