There are five classes in Gears of War 4’s “Horde 3.0.” Though none of them stray too far from Gears’ core running and gunning — there’s no medic, for example — each has its own strengths. There are definite advantages to planning your team makeup carefully, and you’ll want to consider each class’s fortes before diving in.
Soldier: The soldier is the class for players who don’t really want to deal with the class system. It’s the one that lets you play basically how you’d play if there was no class system — using whatever weapons you want, basically not changing your behavior at all. The soldier’s skills include things like extra ammo capacity, extra damage for grenades and assault rifles (like the lancer and hammerburst), and extra damage protection while in cover.
Assault Rifle Damage - +10% Lancer/Retro/Hammerburst damage, with an additional 10% per skill level
These guns are the workhorse weapons and have high fire rates, a 110%+ damage output adds up to a lot of extra damage.
Active Reload Boost - +20% Active Reload bonus, additional 20% per skill level
This applies to all weapons. Pretty huge if you're reliable with active reloads, especially stacked with the above skill. Make sure you empty the clip for maximum effect.
https://www.youtube.com/watch?v=TEoCo0012GYSniper: The sniper is self-explanatory: if you like popping heads with the embar and longshot, the sniper is for you. Snipers can get extra headshot damage, extra ammo for precision rifles, and the ability to mark more enemies at a time, plus the ability to make enemies explode with headshots (at least for lucky players who get that rare skill card; more on that later).
Headshot Damage - +20 damage from headshots, additional 20% per skill level
You gonna be a sniper, you better be good at headshots. You should clean up with this skill.
Explosive Headshots - 75% explosion damage to nearby enemies when one is killed by headshot, additional 75% per skill level
Stack with the previous skill and it's gonna be pretty devastating. Keep in mind that the cards for this skill are very rare, though, so it's going to be very slow going to level it up, or even obtain it in the first place.
https://www.youtube.com/watch?v=deiJEkoMa9oEngineer: Although any team member can craft fortifications at the fabricator, your team should rely on the engineer to do so most of the time. This class gets discounts when building and can create stronger defenses, with better health and higher rates of fire for turrets. The engineer also spawns with an essential tool: a repair gun that can heal barriers and turrets, and replenish turrets’ ammo. Other players can buy the repair gun from the fabricator, but it’s expensive and that energy is best spent elsewhere, with repairs left to the engineer.
Repair Boost - 20% cheaper and faster defense healing with the Repair tool, additional 20% per skill level
As Engineer, job #1 is maintaining the health and ammo of your teams's defenses, you're the only one that can. Being able to do it cheaper and quicker is a no-brainer.
Turret Health - 20% additional health for manned turrets, additional 20% per level
Manned turrets are god-tier defenses, and they're really expensive to replace if they get destroyed. Make sure they can withstand a beating.
https://www.youtube.com/watch?v=_7Q0n9CAU0QHeavy: The heavy is an expert in heavy weapons, including boomshots, mulchers and everything else that makes a big explosion or chews through Swarm flesh like bloody popcorn. This class gets better damage and reload speed on these weapons, plus special abilities like a mortar strike — if you’re lucky enough to get the rare skill card.
Marked Damage - 10% bonus damage on marked targets, additional 10% per level
A damage boost for any weapon so long as the target is marked. Another no-brainer and stacks well with the Heavy's more weapon-specific skills.
Turret Damage - 10% bonus damage from the manned turret, additional 10% per level
It's hard to pick between the various weapon bonuses the Heavy can get, but I feel the turret one pays the most dividends assuming the team can maintain turrets well. Their damage output is already insane and they can pick enemies off from long distance much more effectively than the other power weapons.
https://www.youtube.com/watch?v=iwTneGfjjDkScout: The scout is the trickiest class to play, but also one of the most essential, particularly for teams who plan to tackle all 50 waves on higher difficulties.
The scout gets a bonus when depositing energy from fallen foes into the fabricator, which means this player spends most of their time running around behind enemy lines picking up energy and trying not to get killed. To help they get more health and faster movement, plus the abilities to regain health from shotgun and melee hits and see enemies through walls.
Deposit Bonus - 10% additional power when depositing at the Fabricator, additional 10% per level
Equip this skill and tell everyone else to kindly f*** off from gathering power, and your team's war chest will be so much better for it.
Shotgun Damage - 20% bonus damage with the Gnasher and Overkill, additional 20% per level
What is best in Gears? To shotty your enemies and hear the lamentations of their gibs. Now you can do that even faster and more effectively! Really devastating with the Overkill's rapid fire. (Probably better to use the Health Boost skill if you're playing Hardcore or Insane, though, as getting close to enemies is a big liability there.)
https://www.youtube.com/watch?v=VxYu4g-FdCY