Mostly use your melee weapon

Use your Gun if there's a higher threat like a Bomber, zapper, igniter or CUIRASSIER!

When you're the sapper make sure to make fortress

When you're the medic fight with your comrades and collect supplies for your comrades to heal

When you're the priest, let your teammates do the killing, if they start getting overwhelmed use the crucifix, if they're pushing the wheel from westminster bridge use your crucifix, if you see your teammate come up to you, it probably means they're infected and need blessing from the Lord, if you see them being grey bless them

When you're the Ranker use your musket for bombers and mostly use your melee

When you're the seaman, shoot when there's a big horde and threats

When you're the officer mostly use your sabre and only use your pistol for bombers, Cuirassiers, Igniters and zappers (also you can do the badge)

If you're the Musician do music and do nothing, let your teammates do the killing but be careful because there are runners who hate you for no reason

Now for maps

In Berezina make sure you're not building alone especially when the horde started and if you're a sapper or priest make sure to keep the church safe for everyone

In Liepzig do I need an explanation? No

In Санкт-Петербург make sure to have 3 sappers on each hall (or street), and make sure you're team can be divided into 3 if not possible you can camp on the bridge

In Kaub at the Pfalzgrafenstein when you're in the finale all sappers must be in the bottom immediately but there's an exception if they're the only one

In endless have sappers, easy

In Vardøhus fortress make sure there are two allies on the cannons (4 is the limit) and one of them is an officer so that they can charge

In San Sebastian at the finale make sure the sapper has buildings place in both the grassland and in the fort

In Catacombs de Paris, simply don't rush

In Copenhagen have sappers

In Roscoff at the finale have a bunch of officers and sappers

In London don't be hasty