Heroes are hard to classify because there are no set positions. Each game is different and that's part of what makes it fun. Heroes can be played in multiple ways, each has different properties associated with them, etc.
The way I view this is that each hero has a Role and Properties. A role determines how you function on this particular team during team fights, the laning phase, etc. Properties I see as something being a side benefit to picking that hero.
Farm PriorityFarm Priority is a major deciding factor in a hero's role. Generally, it is broken down into a 1-5 system, with 1 being the highest priority for farm.
Some heroes can be played in multiple ways. This is a major deciding factor as to what way they will be played.
ClassI break classes into 3 broad categories with sub-divisions. These decide how a hero will function on a team, especially during team fights. These have a fairly strong link to farm priority as well.
- Farm Priority = 1
- General Description = heroes that are effective in providing consistent damage output, or DPS.
- Hard Carry = excellent skills for being effective in the late game. Need immense amounts of farm for maximum effectiveness.
- Examples: Faceless Void, Anti-Mage, Morphling
- Semi-Carry = able to carry under the right circumstances, decent carrying ability, but definitely not as effective as a Hard Carry with the same farm
- Bloodstone Carry = heroes that need the regen in order to carry. Typically have a lot of spammable spells that can output a ton of damage.
- Examples: Death Prophet, Leshrac, Storm Spirit
- Snowball Carry (A.K.A. Mid-Game Carry) = heroes that can carry, but need to get a lot of kills in the early-mid game, or need to not die much early on.
- Examples: Night Stalker, Juggernaut, Chaos Knight
- Farm Priority = 2, 3, (4)
- General Description = heroes that are versatile and aid in progressing the game through ganking, pushing, and starting fights
- Hunter = heroes that are good at finding singled out heroes and getting an easy 1v1 kill
- Examples: Bounty Hunter, Bloodseeker, Clinkz
- Roamer = heroes that are most effective bouncing between lanes
- Examples: Vengeful Spirit, Enchantress,
- Initiator = heroes that have a skillset that works well for starting a team fight
- Examples: Tidehunter, Sand King, Enigma
- Opportunist = heroes that are good at ganking and pushing if an opportunity arises such as a lucky Rune, bad positioning on the other team's behalf, etc.
- Examples: Invoker, Templar Assassin, Broodmother
- Farm Priority = (4), 5
- General Description = heroes that are effective with little farm and are therefore able to purchase team items like Wards, Dust, Smoke, etc.
- Second Support = heroes that have support as a secondary task. They typically set up kills, stack the jungle, pull creeps, etc.
- Examples: Leshrac, Enchantress, Rubick
- Hard Support = heroes that excel with little farm, have good early game abilities, and are therefore able to buy almost all the team support items (e.g. Wards, Dust)
- Examples: Crystal Maiden, Venomancer, Jakiro
PropertiesHeroes have properties. These are things that are characteristic of them, and not necessarily their role on a team.
- Heroes that have an escape mechanism like Invisibility or Blink
- Examples: Windrunner, Bounty Hunter, Queen of Pain
- Heroes that are naturally able to take more damage via Strength Growth, an ability, etc.
- Examples: Axe, Centaur Warrunner, Lifestealer
- Heroes that have a skill that aids in taking towers down quickly
- Examples: Pugna, Leshrac, Chen
- Disabler / Crowd Control
- Heroes that are able to help control a fight through stuns, silences, etc.
- Examples: Shadow Shaman, Lion, Bane
- Lane Control & Counter-Pusher
- Heroes that help control the creeps in the lane and their positioning
- Examples: Lich, Tinker, Undying
- Heroes that have a healing spell
- Examples: Dazzle, Omniknight, Witch Doctor