It can be chaotic, intense and frustrating - even for the most seasoned of pirates. But, with some preparedness, this old salt can help ye keep yer skin.
1. BE PREPARED
First, DO NOT PANIC.
In the time ye has before an invasion, gather ammo ye need for yer guns and grenades, fill up yer dagger braces, grab all the tonics ye can get yer hands on. Because once it starts, ye won't be able to.
Nearly all of the enemies are undead, so use Silver ammo in yer guns. Also take this time to arrange your weapons bar. Pretty much all weapons will work against the Undead, but have your favorites at the ready. I usually recommend having a voodoo doll. It's a weapon and healing tool for crewmates.
The goal be the same for all three islands, stop or hold off Jolly's forces until ye can defeat all of them or Jolly Roger hisself.
Jolly's boys seem to know how many pirates are defending, so a busier island will have MORE and TOUGHER enemies. Nearly empty locations will have much weaker foes. This can be a good idea if ye have a large crew or yer guild is tackling the invasion as a group. If yer solo, see if ye can join a crew.
2. TEAM UP
Being in a crew not only give ye a bonus for experience but it means ye can track teammates on yer compass, on the map and have a sharp eye on their health - if ye be a healer. It also let's them keep an eye on ye too, should things go bad.
Try and balance how many pirates defend each location. Remember, Jolly's boys have a set path they take, starting on the beaches and docks. Then, they head inland. So, there be no reason to man a barricade near their goal at first.
Use CREW and GUILD chat if possible once the shooting starts. The public chat will be much harder to follow. And it takes a lot longer to whisper to more than one pirate at time.
If yer healing, go ahead and have some teammates attuned. Even as a healer, I will leave 1 attune spot open so I can attune an enemy.
3. COMBAT TACTICS
Starting with Long Range weapons (Muskets, Single-Shot Pistols, Grenades, Flaming Skull Hex) means ye can take down enemies before they can counter.
As they close in, fall back or switch to Close Range (Blunderbuss, Repeater Pistols, Throwing Daggers, also Whither and Desolation Staff Hex).
Point Blank Range weapons (Swords, Dagger, and Voodoo Doll) can do more damage but yer now at a greater risk of taking damage.
Consider a Broadsword for ye blade choice if using a sword. It can hit more than 1 enemy at a time. And though slower to wield, they tend to do more damage.
Voodoo Dolls mean ye can attune several enemies, then retreat while continuing to attack them - but safely out of their reach.
Take advantage of the narrow passageways near barricades or bottlenecks by concentrating defenses there. These would be the stone bridge on Port Royal, wall archways on Port Royal, the mansion gates, the town square in Tortuga, the rope bridge on Padres, and the mountain pass on Padres.
Check the Compass Map. While ye get messages tellin' how the battle be goin', its still best to check the big map to see which barricades have fallen and which ones need help.
POWDER KEG RUNNERS should only be engaged at LONG RANGE if possible. These kamikaze monsters can take down even toughest pirates. If ye spot one, stay clear. Not only because hitting it with yer sword is suicidal, other pirates may shoot it and KO ye in the process.
If ye spot one coming, shout KEG! or KEG RUNNER! to give mates a heads up to get clear. Give them a moment before opening fire.
The waves will get stronger so be ready to fall back as once they get too tough to hold. Being overrun also adds to the chaos.
If yer using Silver ammo, don't forget to change or use a different weapon when the Stumps arrive.
JOLLY ROGER is simply a tank. yer best bet is to either use Voodoo Doll, throwing Curse, Life Drain and Grave Shackles or blast away from range with Flaming Skull hex or Silver bullets. Once Jolly starts his march, no need to fight any of the other baddies, except maybe to stop a Keg Runner from blowing up yer barricade. Otherwise once Jolly's coming, focus everything on him. There's little ye can do to avoid his attacks, except Hex Ward or Spirit Ward or the Not in the Face ability. Or stay at long range if you don't have much health.
5. TOUGH LOVE
Unless ye focusing on healing and reviving, its oft better to NOT revive mates who are KO'ed in the midst of battle. This doesn't apply if you're a designated healer, obviously.
But, remember - reviving takes ye of out the fight, it takes a long time and makes ye vulnerable. And though you come back Groggy, it can be FASTER to go to jail than wait for someone to revive you, without them also being attacked or KO'ed - especially if facing Jolly himself. You'll need as many hands as possible.
NOTE - Have some Clap O'Thunder potions if possible.