OptionalRule
Adventurer
I wrote a bit about the difficulties of leveling at different points along a characters lifetime in 5e. Not earth shattering but I was surprised to see that 11-19 was about HALF as hard to level as 10th level and this made me reconsider pacing in experience based games, or even expectations on pacing for milestone based games.
5e Advancement Difficulties
5e Advancement Difficulties