Citadel

Citadel is a common plugin on civ servers which allows blocks to be reinforced at the cost of resources. Reinforced blocks must be broken many times before they are destroyed. The durability of a reinforced block can be increased by reinforcing it with a more expensive material. Reinforced blocks also prevent certain player interactions, such as a reinforced door from being opened.

An obsidian block reinforced with stone. From top to bottom, as shown by /ctinfo: durability, NameLayer group, reinforcement material.

Citadel interacts closely with the Namelayer plugin. Blocks are reinforced to a particular Namelayer group, and users on that group can bypass the protections of Citadel for that block.

Citadel is primarily used as a defensive tool. Players generally reinforce their builds, or defensive structures like vaults, to make them harder to grief or attack.

First introduced in Civcraft, Citadel has been included in every mainline civ server since.

Mechanics

In vanilla minecraft, blocks need only be broken once to be destroyed. In contrast, blocks reinforced by Citadel must be broken repeatedly before the block is destroyed. The durability of a reinforced block depends on the material that block was reinforced with.

A reinforced block being destroyed. Each time the block is broken, it reduces the reinforcement durability. The block is destroyed once the durability reaches zero.

Reinforcement Materials

Material	Durability	Maturation time	Acid maturation	Dimension Restriction
Stone	50	30 minutes	2 hours	Overworld
Iron Ingot	300	4 hours	12 hours	Overworld
Diamond	2000	12 hours	24 hours	Overworld
Nether Brick	50	30 minutes	2 hours	Nether
Gold Ingot	300	4 hours	12 hours	Nether
Gilded Blackstone	2000	12 hours	24 hours	Nether

Material	Durability	Maturation time	Acid maturation
Paper	1	1 minute	1 minute
Stone	50	5 minutes	20 minutes
Iron Ingot	300	30 minutes	6 hours
Diamond	2000	4 hours	2 days

Material	Durability	Maturation time	Acid maturation
Stone	25	Instant	N/A
Iron Ingot	250	Instant	N/A
Diamond	1800	Instant	N/A

Restricted Usage

Unless they have permissions on the Namelayer group the block is reinforced to, players cannot interact with reinforced blocks in any way. This includes:

• Opening reinforced containers, such as chests, barrels, or hoppers
• Pulling items out of — or putting them into — a reinforced container with a hopper (unless the container has been marked as insecure)
• Opening or closing reinforced apertures, such as doors or trapdoors
• Tilling reinforced grass or destroying reinforced farmland
• Initiating a redstone signal from a reinforced redstone component. Stepping on a reinforced pressure plate or clicking a reinforced button, for instance, will not send a redstone signal
• Harvesting or planting crops on top of a reinforced block

Tool Durability

Breaking a reinforced block will not take durability off a tool. However, performing the final break which destroys a reinforced block will. This means that destroying a reinforced block with a tool consumes the same durability as breaking a regular block.

Gravity

Reinforced blocks are not affected by gravity. This means that, for instance, reinforced sand will float, even when unsupported by blocks under it.

However, blocks which require a supporting block to be placed on — such as doors, rails, buttons, or torches — still have this requirement, even if they are reinforced.

Modes

Reinforcement Modes

To reinforce a block, you must switch to a reinforcement mode. There are several of these modes, but all work functionally identically: blocks can be reinforced with a reinforcement material (see § Reinforcement Materials), and doing so consumes one of that material. The exact mechanism by which a block is reinforced depends on what mode you are in.

Most reinforcement modes take an optional group argument. This is the Namelayer group that the block will be reinforced to while in that mode. If no group argument is supplied, it will use your default group.

Mode name	Command	Description
Reinforce Mode	/ctr [group]	The most basic reinforcement mode. While in Reinforce mode, left or rick click on a block with a reinforcement material in your hand to reinforce that block.
Fortify Mode	/ctf [group]	Run this command with a reinforcement material in your hand. While in Fortify mode, this material will automatically be used to reinforce any blocks you place. While in fortify mode, any blocks placed are automatically reinforced reinforced with that material. If you run out of reinforcement material, or a reinforcement fails for any reason, Fortify mode will exit.
Easy Mode	/cte	Unlike other modes this only allows reinforcing to your default group. On easy reinforce you can hold a reinforcement material on your off-hand and automatically reinforce blocks you place with it, or hold the reinforcement material on your main-hand and punch blocks to reinforce them. Unlike Reinforce mode this won't generate warnings when attempting to interact with blocks without a reinforcement material, letting you leave it on. However, doing so may lead to accidental reinforcement
Advanced Mode	/cta [group]	The command must be run while holding the type of block you intend to reinforce in your main hand and a reinforcement material in your offhand, you may do so again to add more targeted block types. Advanced mode behaves like fortify mode while allowing you to choose individual groups and different reinforcement types (or, by default, none) for each type block there is.
Patch Mode	/ctp	Used to repair existing reinforcements instead of creating them. While in Patch mode, left or right click an existing reinforced block. It will be repaired to full durability if you have the reinforcement material used to reinforce the block in your inventory. The chance of consuming the reinforcement material is proportional to how damaged the block is. For instance, a block at 95% durability would have a 5% chance of consuming the material.
Normal Mode	/cto	Exits any reinforcement mode and returns to Normal mode. This is the default mode for all players.

Toggle Modes

These modes allow you to retrieve information about reinforcements or affect reinforcements in some other way besides creating a reinforcement. These modes can be toggled on or off independently of a reinforcement mode or of each other. In other words, you could have info mode, bypass mode, and reinforce mode all active at the same time.

Mode name	Command	Description
Insecure Mode	/ctin	Insecure mode allows you to left click a reinforced container to turn it into an "insecure" reinforcement. An insecure reinforcement allows hoppers to move items in and out of the container, in contrast to a normal reinforcement, which will not.
Info Mode	/cti	While in Info mode, left or right clicking a block will cause information about its reinforcement to be displayed, including its reinforcement material and durability. This can be used even on blocks reinforced to a group you do not have permissions on.
Bypass Mode	/ctb	Bypass mode allows you to bypass reinforcements on a group have permissions on. This means that you can treat reinforced blocks as unreinforced blocks when in Bypass mode. When breaking a reinforced block in Bypass mode, the reinforcement material originally used will be returned to you.

Acid Block

Acid (gold) blocks being used to clean up an obbybombing of Icenia on CivMC.

An acid block is the name given to a particular block which can be used to clear reinforced blocks at scale, without manually breaking each reinforced block. Gold blocks have historically been used as acid blocks since their introduction on Civcraft.

To use an acid block, place it underneath a reinforced block, then reinforce the acid block with the same material that the block above it is reinforced with. Depending on this material, the acid block will take a certain amount of time to mature (see § Reinforcement Materials). Once matured, run /ctacid while looking at the acid block to destroy the block above it. This works regardless of how much durability the reinforced block has. Only users with permissions on an acid block's reinforcement group can run /ctacid on it.

/ctacid can be run on many acid blocks simultaneously, as long as they are all beneath the player's cursor when the command is issued.

Note that an acid block does not gradually do damage to the block above it. It only has an effect once it matures and someone runs /ctacid on it.

Acid blocks is one reason why almost all defensive infrastructure (such as Vaults and Bunkers) are built at bedrock. Building on an unbreakable block such as bedrock prevents acid blocks from being used against you.

Acid blocks are often used to clean up Obsidian Bombs.

Decay

Reinforcements can decay if nobody on the group they are reinforced to logs in for a certain amount of time. For instance, if nobody on a group logs in for 3 months, all blocks reinforced to that group will get a damage multiplier of 2 (meaning they require half the breaks to break).

Since a single player on the group logging in is enough to reset decay, decayed reinforcements are uncommon.

Decay steps

Decay state	Inactivity	Damage multiplier
Not decayed	< 3 months	x1 (normal)
Partially decayed	> 3 months but < 1 year	2-8
Highly decayed	> 1 year but < 2 years	16-128
Heavily decayed	> 2 years but < 3 years	256-1024
Completely decayed	> 3 years	>= 2048

Redstone Interactions

TODO rewrite as paragraphs

• Reinforced buttons will only emit a signal if someone from the namelayer is nearby (distance?)
• Comparators cannot inspect the content of a reinforced container block (e.g: chests, furnaces, droppers)
• Droppers and hoppers will not transfer items if the destination block is not on the same reinforcement group.
• Blocks can not be attached to a reinforced redstone component (e.g dropper, dispenser, hopper?) if not on the reinforcement groups.
• Reinforced doors, trapdoors and fences gate will only respond to a redstone signal if someone on the reinforcement group is less than 7 blocks away from it

Command Reference

Usage	Alias	Description
/ctfortify [groupname]	/ctf	Toggles fortify mode
/ctreinforce [groupname]	/ctr	Toggles reinforce mode
/ctadvanced [groupname]	/cta	Toggles advanced mode
/cteasy [groupname]	/cte	Toggles easy mode
/ctinfo	/cti	Toggles info mode
/ctoff	/cto	Turns off all reinforcement and information modes
/ctacid		Activates an acid block
/ctbypass	/ctb	Toggles bypass mode
/ctinsecure	/ctin	Toggles insecure mode
/ctdl		List all possible materials you can reinforce with, in a GUI
/help Citadel		List all commands