Changes

Diablo is highly replayable thanks to its randomly generated levels, with every map that the player encounters being unique compared to the last. This randomness extends to the monster population as well, though they are generated from a group appropriate for that level. In addition, in Single Player mode there are only three core missions as the rest of them are drawn from several pools, making it impossible to complete every quest in one setting. Either way, only the last two quests are compulsory (although it is recommended to complete the voluntary missions to gain experience and items, and to learn more of the backstory). Given this arrangement, no two playthroughs of the game are ever exactly alike. By contrast, Diablo II is much more linear even though many of its maps are randomly generated as well(only noticeable in the wilderness areas), as the player will encounter the same levels and quests (many of which are compulsory) upon each playthrough.

The Rogue is somewhat like the [[Amazon]] "Bowazon" subclass. While the Amazon can shoot fire-enchanted arrows (Fire Arrow and Immolation Arrow), the Rogue is able to supplement her arrows with the occasional Firebolt and Fireball. Whereas the Amazon has to use spears and javelins (weapon types found in D2 but not D1) to get make use of lightning elemental damageskills, Rogue can inflict this damage directly by casting lighting spells.

The Warrior has no multi-hit nor multi-target skills like the Barbarian's Whirlwind or Paladin's Zeal. However, a Warrior can use the spell Teleport for "Telekilling" in a similar manner to a Barbarian using Leap or Leap attack Attack to reach those pesky monsters that are prone to running away. The Warrior can also use Holy Bolt as an offensive spell against the Undead like the Paladin. The Warrior may also make use of Stone Curse followed by a Fireball to take out a group of enemies around his target.

While the Diablo characters are very different in their design, they have a great deal of overlap as well. There are no unique skills /spells in Diablo, and other than one "ability" each character can use inherently, there are no skill trees of any type. Magic exists in the game, but it comes from spells which all characters can access, either from scrolls, charges on staffs, or by learning the spell by reading a [[D1 Spellbooks|Spellbook]]. Spells increase in power and decrease in mana cost with each book that your character reads, and they are hard capped at level 15.

All characters can read all the same spellbooks, though since there are magic requirements to read them, Rogues and especially Warriors need special +magic equipment to learn higher level spells, and to read higher levels in the same spells. D1 spellbooks have no skill trees of any type (no spell prerequisitesnor level requirements), although certain spells such as Nova or Apocalypse do not have a spellbook and instead are only available on staves or scrolls.  In D2 the skills/spells for that particular class are immediately available to level up, as soon as a player reaches a certain level and as long as they have the prerequisite skill(s). By contrast in D1 However the type and frequency of spellbooks available to the player are generated at random which is often to the player's frustration, a player searching for a particular spell that they wish to level up will end up making several different trips to Adria's shop until the desired spellbook comes up for sale, if that spellbook is not found in the dungeon (usually a tomb or bookshelf) . In D2 the skills/spells for that particular class are immediately available to level up, as soon as a player reaches a certain level and as long as they have the prerequisite skill(s); although it is generally recommended that players spend their skill points wisely which typically means focusing on only a few core skills.