From Diablo Wiki
Gear sets is the term the D3 Team uses to describe the different levels of armor in Diablo III.
There are 16 gear sets in Diablo III. A "gear set" is not an Item Set, a group of themed magical items with interrelated magical bonuses. "Gear set" is just a term the developers use for pieces of armor of the same approximate item level. The lowest level items, for each armor slot, would make up one gear set. These items would be things like cloth armor, plain leather boots and gloves, etc.
The quality of items found throughout the game (over all 4 difficulty levels) will increase gradually, as characters upgrade their gear from light cloth to heavy plate and beyond. All armor is themed appropriately for each class, and every piece will look different depending on which class or gender wears it.
A key point to remember is that there are no exceptional or elite pieces of armor in Diablo III. The 16 tiers of gear sets progress from Act 1 Normal up through Act 4 Inferno, rather than repeating in each difficulty level as they did in Diablo II. This means that end game characters in Diablo III will look like it, with their armor all from the higher gear sets, rather than mixing and matching elite versions of leather or chain armor with some plate, as was often the case in Diablo II.
- Looking for a Gallery of gear sets?
 Mix and Match Armor?
The Diablo III team has often stated their desire to avoid the mismatched, "clown suit" armor possible in Diablo II. They want the different items to mesh and blend together, at least somewhat, in Diablo III.
It's known that players will have the ability to use armor dyes to change the color scheme of their armor. After months of confusion, Bashiok finally confirmed that there are indeed 18 different types of every armor item in the game, although at some point that number was reduced to 16.
Wearing a full kit of matching items from a single tier will give any character the sort of cohesive, themed look that's seen in the various photos on this page. Wearing pieces of armor from different tiers gives varying aesthetic results.
 Gear Icons
In Diablo III, unlike Diablo II, the icons for the items a player will wear will match what they look like in-game. The image to the left shows the Wizard's inventory pane open, and then, to the side, the actual gear displayed in the game. The icons match up nicely with it, showing precisely what the icon says.
If the Wizard were to drop the chest piece (for example) on the ground, and a Barbarian picked it up, it would look completely different on the Barb.
 BlizzCon 2010 Gear Set Previews
During the weeks before Blizzcon 2010, Blizzard previewed six gear sets, two each for the Barbarian, Witch Doctor, and Wizard. They didn't include much information about the sets, but as seldom as new Diablo III visuals are released, fans were quite excited to see the new sets all the same.
Each one posted touched off extensive discussion and debate on the pros and cons of the armor, and there were frequent fan-recolorations and modifications of the more-controversial aspects of the gear sets (especially the male Wizard's helm). The news posts and a few related follow ups are listed below; click through to relive the delight and argument that these images spurred. The images themselves are displayed below, with the male and females combined by class.
- Male Witch Doctor gear set, September 30, 2010. The court jester style set went over well enough.
- Female Wizard gear set, October 5, 2010. The second gear set was well-received by fans, proving once again that everyone loves Asian girls.
- Female Barbarian gear set, October 7, 2010. The first gear set image
- Female Witch Doctor gear set, October 12, 2010, was fairly well-received.
- A fan remake turned up a day later all the same.
- Male Wizard gear set, October 13, 2010, set off the biggest debate of all, about his huge "starfish" hat.
- Male Barbarian gear set, October 18, 2010. The last of the sets, this one did not set off any big arguments with general approval of the ram's horns helm.
 Blizzcon 2010 Panel Gear Sets
More Gear sets were shown off during the Crafting Sanctuary Panel at Blizzcon 2010. These images are compilations, showing several different gear sets in one large image for easier viewing.
There were three sets shown on the male Barbarian, with his animal-themed armors getting top billing.
The male Witch Doctor's sets made a stir by how exotic their designs were. The lower right set in this 2x2 image is his most famous set, one fans are calling the tentacle gear set. The black limb-like things along the outside of the shoulders and helm wave around, in constant motion. The effect doesn't translate well to a still image, sadly.
 GamesCom 2011 Gear Sets
These sets were introduce during a presentation at GamesCom 2011, with accompanied chat about the Inferno difficulty. The last set of items in each picture is found in Inferno or otherwise found in late-game hell difficulty.
 Retractions and Changes
In an unexpected turn of events, perhaps based upon fan-feedback, the Wizard's notorious (nefarious?) starfish hat, and his shoulder pads were revealed to have been changed over the course of development, showing that Blizzard does indeed listen to its fans.
 Diablo II Gear Sets
The term was not used by the Diablo II developers, but they clearly structured the armor in that game into gear sets as well, of a sort. They weren't like the Diablo III gear sets, since there are very uneven amounts of different item types in Diablo II (many more types of helms or body armor than gloves or boots, for instance), and they don't line up to create matching outfits. Armor items in Diablo II look different on each class, but not as different or stylized as the do in Diablo III.
Still, it can be useful to compare the D2 characters, as seen in the 3D models below, before it was converted and compressed into the tiny 2D sprites that are seen while playing the game.
These images were posted in opposition/comparison to the first few Diablo III gear sets, in October 2010. See the original news post on Diii.net for the full debate and lengthy fan discussions.
|Items of Diablo III  Item Basics Normal Items Legendary Armor I Legendary Armor II Legendary Weapons 1h Legendary Weapons 2h Item Sets|
|Item Basics||Item Modifiers||Inventory||Artisans||Merchants||Miscellaneous |
|Armor - Class-Specific||Weapons - Class-Specific||Crafting Items||Other Items |
|| • Blacksmith Plans
|Waist||Wrists & Hands||Legs & Feet||Head |
|| Voodoo Masks - WD|
| Chest Armor
|| Amulets cont.
|| Rings cont.
40) Puzzle Ring
|| Sources - Wiz|
|| Fist Weapons - Monk
|| Mighty Weapons - Barb|
|| Daibos - Monk
|| Bows |
|Item Sets |