From 1d4chan
How Seekers were envisioned.

Not to be confused with the Quidditch position of the same name from the Harry Potter series.

Seekers are Wizards of the Coast's attempt at making a primal controller that is not called a druid for 4th Edition. The result is a class whose primary mechanic revolves around imbuing weapons with primal spirits and then throwing said weapons as hard as they can at enemies. In many ways Seekers are like the unpopular kid from druid school who couldn't take an animal form or get any living animals to be friends with him so he dropped out, moved back with his mom, and now binds spirits to arrows and shoots them at enemies as a way of getting back at them for not letting him join in their reindeer games.

Seekers can choose to use either bows/crossbows or thrown weapons (the latter of which return to your hand after attacks are made, with no further explanation on how that makes sense other than "the spirits do it"). This is, in fact, the entire problem behind the seeker is that none of its features seem to make any sense whatsoever. It is a ranged Controller class that, according to the PHB3, subclasses in either striker or defender. The defending option focuses on daring people to attack you, and then running away to hide behind your party's real defender. Luckily, this part is simple as he will be easy to spot, he will be the one not holding a bow and has likely already marked or will mark one of them.

Despite the generally lackluster power/role/feat selection for this class the seeker does have the occasional useful power. Like the ability to slow/shiftlock at-will, or the encounter power Feyjump Shot which allows you to swap two enemies' places on the field and daze both of them. There are also more colorful things like causing trees to grow out of bad guys, or (my personal favorite) having a swarm of spirit bats attack your enemies because, presumably, all the living bats were busy helping out druids.

Still, the lack of many hard controlling powers, or the ability to enforce the soft control options available leave the Seeker way outclassed in the controller department. There are simply better choices out there, even for the same power source.

But if all you want is to rely on dead things to help you survive combat and to shoot people with trick arrows this is the class for you.

What Seekers actually look like: flavorful but ineffective.

The Seeker was basically made by taking the "magical archer" aspects of the Ranger (which had been dumped for that edition, on the justification that the Ranger had always been a pretty shitty spellcaster anyway and most people ignored it), with a little of the Arcane Archer prestige class added in, and doubling down on the "Druidic" aspects of old Ranger flavor, a matter which was revisited during the controversial "Essentials" days with the Scout.

If they had come out earlier, or just gotten any sort of support (as they released with PHB3, they missed out on getting anything from Primal Power and had to rely on the drippings of Dragon Magazine for more choices) before Wizards decided to jump onto the Essentials Crackhouse, then they surely would have become the iconic Elf class, since their blend of Primal Spirits-fueled magic and archery talents is a natural mesh for elfin lore - plus, since Seekers rely on Dexterity and Wisdom, and elves get bonuses in those stats, it's a match-up as optimized and iconic as the Dragonborn Sorcerer/Paladin or the Tiefling Warlock.

It's arguable whether they did better than Runepriests; Seekers got two Class Acts articles, with "Savage Archers" in #389 giving new archery powers and four new magic bows, whilst "Seekers of the Moonrise Vanguard" in #413 gave them new powers and the Moonrise Stalker Paragon Path; in comparison, Runepriests got a "Class Acts" in #394 that was just rune-flavored alternative rewards for everybody ("Lost Runes of Unmaking"), a new subclass in #398's Unearthed Arcana ("Ignorance is Blessed"), and a second Class Acts in #404 ("Shan Zi of Kara Tura") that gives them a new subclass, new powers, two new feats and the Enlightened Word Paragon Path.

Dungeons & Dragons 4th Edition Classes
Player's Handbook 1: Cleric - Fighter - Paladin - Ranger - Rogue - Warlock - Warlord - Wizard
Player's Handbook 2: Avenger - Barbarian - Bard - Druid - Invoker - Shaman - Sorcerer - Warden
Player's Handbook 3: Ardent - Battlemind - Monk - Psion - Runepriest - Seeker
Heroes of X: Blackguard - Binder - Cavalier - Elementalist - Hexblade - Hunter
Mage - Knight - Protector - Scout - Sentinel - Skald - Slayer - Sha'ir - Thief
Vampire - Warpriest - Witch
Settings Book: Artificer - Bladesinger - Swordmage
Dragon Magazine: Assassin
Others: Paragon Path - Epic Destiny