Roles have always existed. If a person disagrees then I'll jump to an example predating 2008 just to reinforce the idea.
"From the game's early days back in the 1970s to today, the D&D game has used four basic structures for characters. Nobody has ever given these structures formal names, so for purposes of this article we'll call them Sturdy Brawler, Stealthy Rascal, Arcane Spellslinger, and Divine Guardian. Each of these character types contributes to a party's success in a different way, and the most effective parties have at least one character to fill each role."
Skip Williams
http://archive.wizards.com/default.asp?x=dnd/cwc/20061226
The only difference between 4e and other editions is that 4e specified roles for classes in the rules (which could be broken or circumvented) while other editions allowed players to specify roles for their PC's using classes that excelled within certain roles. Not a huge difference and largely that of perspective, but unassigned class roles seems more open to me too.
The character class archive lists various roles that predate 4e among the existing classes. Bards were listed as party multipliers, for example.
The following information is directly from the linked article:
Sturdy Brawler -- Physical combat is what these characters do best. When a party is on the move, these characters are the vanguard, boldly leading the way. Thanks to their position at the party's front, they're usually the first characters to witness an encounter unfolding. Their position at the front of a group on the march also leaves them in the best position to decide exactly where the party goes next when the group is exploring an unknown area.
In a fight, the party's sturdy brawlers generally are the first to attack the foe, usually by moving in and pinning down key foes with melee attacks. Once a battle is in progress, these characters form a fighting line that shields more vulnerable party members from attack. Their heavy armor and high hit points allow them to bear the brunt of the enemy's attacks.
Character classes that are well suited to the sturdy brawler role include the barbarian, fighter, and paladin from the Player's Handbook.
Stealthy Rascal -- These characters can take the fight to the enemy fairly well, but they often do better with a more subtle approach to adventuring. They generally have skills that allow them to serve as a party's eyes and ears. These characters also often have interaction skills that make them the most able negotiators in a party, which can prove handy when combat doesn't seem the best option.
Stealthy rascals often find themselves in the thick of that action during combat, especially if they've moved away from a group to scout the way ahead. Even if they take a more prudent approach, they do best when working in concert with the group's sturdy brawlers. Stealthy rascals can pair up with the group's more martial foes to set up flanking attacks or at least protect their allies' flanks. They're also mobile enough to bypass or penetrate the enemy line and attack leaders or spellcasters skulking in the rear.
Character classes that are well suited to the stealthy rascal role include the bard, ranger, rogue, and monk from the Player's Handbook.
Arcane Spellslinger -- These characters often serve as a party's heavy artillery, using spells that literally blast away massed foes. An arcane spellslinger's spells also can clear away or help circumvent obstacles that defy mundane assaults, reveal hidden information, and provide many other effects that expand a group's options for dealing with an encounter.
Character classes that are well suited to the arcane spellslinger role include the sorcerer and the wizard from the Player's Handbook.
Divine Guardian -- While divine guardians can hold their own in combat, their true power lies in the spells and granted supernatural powers they wield. Most divine guardian spells serve to protect, reinforce, or revivify allies, but they also have spells that can defeat foes or achieve other useful results.
In a fight, a divine guardian can serve on the front line fairly well. Depending on the spells the character has available, a divine guardian also can do fairly well by hanging back with the group's arcane spellslinger and launching spells at foes. This approach keeps the character close to the vulnerable arcane spellslinger in case that character needs quick healing or a bodyguard. It's also possible for a divine guardian to switch between these tactics from fight to fight or even from round to round within a single encounter. A divine guardian with ranks in the Concentration skill can use that rule for casting spells defensively and casting spells right from the front line.
When you're a divine guardian, everyone in a party looks to you for lifesaving healing, especially the group's sturdy brawlers, who tend to absorb considerable physical punishment. All the group's fighting characters can benefit from your presence in the front line in a battle. If nothing else, you'll offer foes an additional target and so dilute their efforts at least a bit. You also can fight in partnership with an ally, working to flank enemies while protecting the ally's flanks. If you travel in a group's rear or center, you'll usually be in the best position to rescue an ally who has fallen prey to an ambush or trap, either with a spell or literally by dragging the hapless character out of danger. As noted earlier, you'll do well to compare your spell selection with whatever the group's arcane spellslinger carries to maximize your group's magical potential.
Character classes that are well suited to the divine guardian role include the cleric and the druid from the Player's Handbook.
Generally, players sort out roles as melee combat, ranged combat, healing, skill specialization (typically stealth or social interaction), artillery (AoE and burst nuking), support, or lock-down / control. Sometimes other specialized perceived roles appear like summoning or general utility. Again, this is done by player perception and build instead of specific role designation. It also largely matches up the above in varying degrees with cross-over and shared design space. Spellslinger is the offense focused party spell caster, divine guardian is the support spell caster, stealthy rascal is the skill specialist, and sturdy brawler is the tank / defender.
My perception of classes that are good at covering roles are:
Melee combat -- barbarian, fighter, monk, paladin, ranger
Ranged combat -- fighter, ranger
Healing / Support -- bard, cleric, druid, paladin
Skill Specialization -- bard, monk, ranger, rogue (monk for some shadow monk abilities and good ability focus for skills)
Artillery -- sorcerer, warlock, wizard
Control -- bard, druid, sorcerer, wizard
Much of those are general opinion and exceptions exist. I think the design team still gave us 4 typical groupings:
Heavy combat -- barbarian, fighter, paladin
Skirmisher -- monk, ranger, rogue
Support -- bard, cleric, druid
Artillery -- sorcerer, warlock, wizard.
Hopefully we're back towards on topic discussion. ;-)
