The difficulty of respecting changes from game to game. Diablo 2, for example, gave Diablo 4 Gold
players a single respec for each difficulty,
for a total of three possible respects on each character. Diablo 3 went the completely opposite direction and Diablo 4 items
let players change abilities.
and builds at will, at no cost. The respec system in Diablo 4 is somewhere in between.