Classes were first introduced in Worms Revolution. Each class has strengths and weaknesses as well as differently-pitched voices. Players can mix and match them in any order. They later reappear in Worms 3, Worms Clan Wars and Worms Battlegrounds.
The main class throughout the series. The Soldier is a balanced Worm meaning no strengths or weaknesses. They can manually detonate Grenades and other timed weapons in Worms Clan Wars. Players automatically start with a full team of Soldiers. Their voices remain unchanged.
The Heavy is a large and bulky Worm. They move very slow and cannot jump very far, and can take damage from short falls. However, the Heavy is much more powerful and can fling Worms great distances when using a Baseball Bat or Fire Punch and cannot easily be launched into the air from weapons. Another drawback is when using the Jet Pack it moves slowly and runs out of fuel very fast. Heavies have a low-pitched voice.
In Worms Clan Wars, they make larger explosions with any weapon, and huge death explosions that can be fatal to nearby Worms. Generally, they deal more damage. (Ex: 30 damage [standard 25] with a Shotgun.)
The Scout is a small Worm. Scouts can move faster, jump further, fly great distances with the Jet Pack (along with extra fuel) and fall down large gaps without trouble. However, because of their size they are easily flung when hit with weapons, which is why caution is advised when near the water or other hazards. They are also the weakest class, causing less damage with any weapon they use, for example, their Shotguns do 20 damage instead of 25. A unique ability is that when using a Blow Torch, Scouts can create a hole where other Worms can't fit through. Scouts have a very high-pitched voice.
In Worms Clan Wars, Scouts can see the contents of nearby Crates at the start of their turn (similar to the Crate Spy utility from older games in the series) and can walk over Mines without triggering them.
The Scientist is a Worm with a big brain. They have the same movement as Soldiers. Their ability is granting all Worms on their team 5 extra health points each turn while alive. Scientists can also use improved versions of Electromagnets, Sentry Guns, and Girders that last longer and can withstand more damage. However, Scientists will do less damage when using any weapon, albeit more damage than a Scout. Scientists have a slightly high-pitched voice.
From Worms Clan Wars onwards, the Scientist will only heal friendly Worms when near them. They can also cure poison to their teammates or themselves.
Also, when a Scientist uses a Lightning Strike, it resurrects dead (not drowned) Worms with 50 HP, as opposed to 30 HP.