There are a lots of different kinds of troops in Boom Beach. Let's take a quick look at the different troops you get to use when invading enemy islands.
These guys are the bread and butter of your army, especially during the early levels. They are very strong against single-target defenses, which they can overwhelm with their large numbers.
The heavy soaks up a lot of damage but can't cause very much of his own. Use the heavy as a "meat shield" to protect other troops.
The Zooka has low hit points but dishes out extraordinary damage. Use her with a Heavy to keep her protected.
Warriors are fast and deadly and heal themselves when they cause damage. They're vulnerable to splash damage attacks, so be careful! They're best used when rushing the HQ and once you have Smoke, you can really do some damage with them.
It's a tank! Need we say more? Big and slow and can take a beating.
The Medic can't do any damage on his own, but he heals other units.