Diablo vs WoW controversy
From Diablo Wiki
Even since the art controversy started, people felt Diablo III was far to "comic-y" and shared too many attributes with WoW. Since both are in the RPG genre, they are bound to share many common traits, and since WoW was heavily inspired by Diablo II, a lot of ideas have come from D2, through WoW, and returned to Diablo III.
This uproar over the similarities between the two games seems to be primarily a vocal minority of players, similar to the art controversy.
 Similarities with WoW
- Is an RPG, and therefore both inculde several genre-defining features.
- Gold is used as a primary resource for player-player trade.
- Auction House is planned.
- Skill system works similarily to the World of Warcraft talent system.
- Uses particle effects to make massive spells and glows in general.
- Automated status point distribution system.
- Diablo- Isometric camera
- WoW- First to third person free floating camera.
- Diablo- A focus on one against many, with one on one challenges.
- WoW- A focus on one on one, with one against many challenges.
- Diablo- Completable with a single player, giving the feeling that it is you against the world.
- WoW- Group/Raid only content, gives the feeling that you are taking part in a war.
- Diablo- Fast paced, often blurred combat.
- WoW- Slower, more focused combat.
- Diablo- Wide variety of epic skills, lets the player choose how they fight and makes them feel legendary.
- WoW- Smaller more specialized skill set, allows the player to efficiently complete their role.
- Diablo - completely damage oriented class design
- WoW - Tank, heal, damage class separation
- Diablo - point and cast/perform action (ideal with an isometric view)
- WoW - select and switch through targets and cast/perform action (at least for most damage spells, except AoE)