Below are the biggest changes in this update:
ExilePearl is replacing PrisonPearl, but you can upgrade Exile pearls to Prison pearls.
This means that when you kill a player with an ender pearl in your hotbar, they will be trapped in an Exile pearl. Exiled players aren't allowed within a large radius around the Exile pearl, or inside the bastions of groups that have disallowed them entry. This includes City Bastions (see below), so keeping Exiled players you don't like out of your town isn't super expensive.
Exiled players also have certain global restrictions. You can view the full list here, but the highlights are that Exiled players:
- Can't attack other players (even if attacked)
- Can't use buckets (otherwise, they could grief pretty easily)
- Can't light fires
- Can't place TNT
- Can't use beds
- Can't use potions
- Can't use ender pearls
- Can't kill certain mobs or any named mobs
- Can't use local chat
- Can't place or damage bastions
- Can't damage Citadel reinforcements
- Can't place snitches
In short, they are pretty much useless for causing trouble. If Exiles are causing you trouble, killing them will tell you where their pearl is.
There is also no more /ppkill, and /ppsummon is now a request you must accept.
City Bastions are a new version of Bastions designed for use outside of vaults. They are much cheaper than normal bastions, and they cover a much larger area. The downside is that they don't block pearls or prevent block placements, but they do prevent reinforcements. This means they are good at preventing grief in your city, but bad at preventing vault breaks.
Meme Mana (also known as essence) is the resource used for repairing and upgrading Exile and Prison pearls. You get mana for logging in each day, and you get more mana per day if you log in consistently, up to a maximum. If you log in every single day, you generate about enough essence to keep one other player Prison pearled indefinitely, or eight other players Exile pearled indefinitely. This means that a town with three active players can't keep more than three other players Prison pearled (or 24 other players Exile pearled) without outside support.
If you stockpile your mana without spending it on pearls or trading it away for too long, it starts decaying. This means that you can't stockpile ten years worth of mana before the start of a war, so you don't get the "coal problem" where everyone has enough coal blocks to keep the rest of the server pearled for ten years.
For more information, you should read the official guide.