Hey Guys, I'd like to take a second to talk about the Sanctuary Mod that Psygate (e.g. fluffly devops owlman) has put together for us. From talking with a lot of folks there seems to be a general misunderstanding of what exactly goes on when you make a sanctuary. For clarity sake I'll explain below the information I've been to piece together via testing and talking with the staff. Let's get started.

Establishing a Sanctuary

The wiki covers this pretty good. You crate your sanctuary block with Quartz and Gold, then slap it down in the middle of what your soon to be sanctuary is. For those who haven't seen it, it looks like a typical sponge block that has an enchantment shine. As explained in the wiki, values are given as a radius and on first placement you gain a radius of 1. You must reinforce the sanctuary with a material (stone/iron etc) to assign it to a group. Simply placing and doing /punch will assign it your own personal group. Make sure it is assigned to your towns group if you want others to build within it.

Growing your Sanctuary

If you haven't done this before, the first time you go about growing your sanctuary you may be confused if it worked or exactly how to do it. When your sanctuary block is placed it starts with a radius of 1 and a hp of 0/500. Over the course of 5min it will recover to 500/500. It is safe to say that every min, the sanctuary appears to recovery 100 hp. This linear recovery of hp also seems to be consistent regardless of the times upgraded. Additionally, each upgrade increases the hp by an extra 500. Sanctuary blocks may only be upgraded when they're at full hp, so keeping tabs on the health prior to an upgrade is important. Make sure you understand this concept before attempting to upgrade.

So under the assumption you have placed your first sanctuary block, waited until hp is full (5min) you may upgrade your Sanctuary by providing it the required material. To identify what required material you need, grab one of the books out of the sanctuary's inventory and check the last page. Be careful to only provide the sanctuary with no more than the required materials for each upgrade. It appears that the inventory is cleared upon each open and any excess or invalid materials are removed. (e.g. Upgrade required 1 Quartz, you put in 10 Quartz, you will lose 9 Quartz) It is also worth mentioning that books provide a snapshot of the sanctuary at time of extraction. The book you pulled out will display outdated information once anything has changed with the sanctuary. You can pull out new books at any time.

Material Costs

Although it is not documented on the wiki, the materials that are required to grow the sanctuary are Quartz Blocks and Gold Ingots. The cost initial starts out low for Quartz blocks and increases into double digits per each radius upgrade. At some point near a hundred upgrades (100 radius), the additional material of gold ingots becomes a requirement. Other nations may be able to confirm if other quantities of materials are required beyond gold.

Edit: HiImPosey details below that at 200 it requires diamonds.

Sanctuary Protection Mechanics vs Amethyst Protection Mechanics

To understand the difference between the two protection methods, make sure you have a good indication of how Amethyst works. A brief summary would be: Amethyst allows a player to add an additional number of breaks onto a block before it is in a vanilla unprotected state. This could mean that a dirt block may take 200 times to break before it can be removed by a non-member of the protecting group. It is worth pointing out that blocks under Amethyst are "normalized" to have varying break counts based on the mining time of the block. A good example of this would be the values between two blocks reinforced with stone. A chest takes 143 breaks while an obsidian block takes 6 breaks.

Sanctuary on the other hand does protections similar but differently. The first is that all blocks protected get a blanket 100 breaks, regardless of the base block. In cases where it is obsidian, 100 breaks is much greater than 6 if comparing stone reinforcements. In other cases, such as a wood plank (200 breaks with stone), it is not as good. A valid strategy would be to selectively reinforce material with stronger reinforcements (Emerald) for higher value items if you know the break count is going to be higher from that.

With Amethyst, when a block is reinforced, there is a material that is stored within that block. Upon destruction via bypass, you reclaim both the source block and the material. You can then take that source block and material and reinforce that block elsewhere. This is where Amethyst and Sanctuary start to differ greatly. Sanctuary does its reinforcement one time as the sanctuary upgrades happen, across all blocks within the radius. This includes air blocks. So after a block has been consumed by the sanctuary bubble it should be protected. Now when a block is destroyed in a sanctuary, unlike with Amethyst, there is no material given back. The block that is destroyed is now forever unprotected by sanctuary. It, like any blocks outside of the sanctuary, have no permissions. To be clear, a destruction of a block in this context is either bypass or an outsider removing all the breaks.

To better visualize what's happening with protections, imagine your sanctuary is a column of pure smoothstone from 0-255, and you are somewhere in the middle of this massive column. The second you start to dig your way around within this column, that smoothstone gets broken bit by bit. You can always replace back what you've dug, but those replacements are going to be cobble unless you manually make more smoothstone for replacement.

A side note about air blocks. The reason it's worth mentioning those is that you never destroy air, but place material into the air space. Since no destruction takes place, the break count is not lost and is carried over into the new block.

Sanctuary Hitpoints

Every sanctuary has hitpoints, which can be displayed either in the book or the sanctuary scoreboard. As your Hitpoints lower, the radius size decreases. If you're curious about your current effective radius size you can run your hitpoints through this calculation: (current hp - (current hp % 500) / 500)

Hitpoints themselves can be reduced by two ways currently: attempted placing of blocks and destruction of blocks. For recovery, as described above, there is a linear recovery rate of 100 hp/min. This is only in effect if the field hasn't been attacked recently stated in the wiki. In actual testing, the field seemed to still recover quickly. Also, do know that your sanctuary block (sponge) is only as protected as you make it. Keeping it in the open with a stone reinforcement is a good way to lose it quickly.

What Sanctuary Really Does For You

From what I've observed Sanctuary really provides your town with four main things.

1. It stops you from being creamed in your territory. So claims the wiki, being killed in your sanctuary will not result in you being locked away to The End. It stops enemies from using ender pearls in your radius. Edit: I can't read. See Tiny's better response to this in the comments.

2. It provides your hovel/town/nation with a clear boundary others can see when they enter. With this it reinforces the idea that destruction of material within this zone may not be worth the effort.

3. It prevents block placement. Non-group members will not be able to place blocks within the zone. Attempted placing of blocks will reduce your hp at a slow rate.

4. It reinforces blocks you wouldn't bother to do. Mostly speaking it is reinforcing the ground as an anti-tunneling device. It is still possible for anybody into your area, but they're going to be going through every block 100 times to do so.

What Sanctuary Does Not Do For You

1. It does not provide reinforcement to blocks that have been destroyed, post sanctuary placement.
   
2. It does not create a strong reinforcement for surface buildings. Impossible to tell if an air block had been occupied and broken prior to construction. Dogs with Bees are the only way to combat this.
   

Final Thoughts

Sanctuary is a good plugin, and does fill in a gap where traditional Amethyst protect does not. I think for many of us, or at least those I talked to, we all made assumptions that it was a direct upgrade of Amethyst.