The maximum character level in Diablo II is 99.
Characters gain experience by defeating monsters and completing quests. Each level grants attribute points and, at most levels, a skill point, allowing players to develop specialized builds such as a whirlwind Barbarian or a frozen-orb Sorceress.
Reaching level 99 is deliberately difficult because experience requirements rise sharply at high levels, while later difficulties and stronger monsters become increasingly dangerous. The level cap applies to both the original game and its Lord of Destruction expansion.
The cap is sometimes confused with the maximum number of skill points or the level requirements of individual items. Those systems are separate: a level-99 character has accumulated many skill points, but equipment and builds can still impose their own requirements.