Citadel

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

Part of a series on
Mechanics and Plugins
Core Mechanics
Citadel NameLayer Bastion Snitch Exile Pearl
Common Mechanics
Orebfuscation HiddenOre Chat Factory Enchanting Realistic Biomes Item Exchange Brewery Essence Kira
Minor Mechanics
Spawning Chunk Limits RailSwitch Arthropod Egg Combat Tag Elevator CastleGate One Time Teleport Commands

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.

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	30 minutes	Overworld
Iron Ingot	300	4 hours	6 hours	Overworld
Diamond	2000	12 hours	1 day	Overworld
Nether Brick	50	30 minutes	30 minutes	Nether
Gold Ingot	300	4 hours	6 hours	Nether
Gilded Blackstone	2000	12 hours	1 day	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	50	1 hour	2 hours
Iron Ingot	250	12 hours	15 hours
Emerald	500	1 day	1 day
Diamond	2000	2 days	2 days

Material	Durability	Maturation time	Acid maturation
Stone	50	5 minutes	30 minutes
Basic reinforcement	250	20 minutes	2 hours
Decent reinforcement	750	3 hours	8 hours
Good reinforcement	1500	10 hours and 40 minutes	1 day
Rapid reinforcement	1500	5 minutes	1 day
Best reinforcement	2000	42 hours and 40 minutes	48 hours

Material	Durability	Maturation time	Acid maturation
Stone	25	10 minutes	10 minutes
Iron Ingot	250	1 hour	1 hour
Diamond	1800	1 day	1 day

Material	Durability	Maturation time	Acid maturation
Stone	25	—	—
Iron Ingot	250	—	—
Diamond	1800	—	—

Material	Durability	Maturation time	Acid maturation
Stone	100	10 minutes	30 minutes
Iron Ingot	750	1 hour	8 hours
Diamond	3000	10 hours	36 hours
Bedrock	3000000	5 minutes	5 minutes

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

Citadel has several modes which players can enter into or exit from at any time. These modes change how players reinforce blocks or interact with reinforced blocks.

Type	Mode	Command
Reinforcement Modes	Reinforce Mode	/ctr [group]
	Fortify Mode	/ctf [group]
	Easy Mode	/cte
	Advanced Mode	/cta [group]
	Patch Mode	/ctp
	Normal Mode	/cto
Toggle Modes	Insecure Mode	/ctin
	Info Mode	/cti
	Bypass Mode	/ctb

Reinforcement Modes

These modes change the mechanism by which players reinforce blocks.

By default, players are in Normal mode, which does not allow blocks to be reinforced.

Reinforce Mode

/ctr [group]

Reinforce mode is the most basic reinforcement mode. While in Reinforce mode, left or rick clicking on a block with a reinforcement material in the player's hand will reinforce that block.

group is the NameLayer group blocks will be reinforced to. If not supplied, it will use the player's default group.

Fortify Mode

/ctf [group]

The command for Fortify mode must be run while holding a reinforcement material in the player's hand. While in Fortify mode, any blocks the player placees will automatically be reinforced with that material. If the player runs out of reinforcement material, or a reinforcement fails for any reason, Fortify mode will exit.

group is the NameLayer group blocks will be reinforced to. If not supplied, it will use the player's default group.

Easy Mode

/cte

While in Easy mode, left clicking a block with a reinforcement material in the player's hand will reinforce that block. Although similar to Reinforce mode, Easy mode allows players to right click blocks without the risk of accidentally reinforcing them. Additionally, Easy mode does not take a group argument, and can only reinforce to a player's default group.

Advanced Mode

/cta [group]

The command for Advanced mode must be run while holding a block in the player's main hand and a reinforcement material in the player's offhand. Until Advanced mode exits, whenever that block type is placed, it will be reinforced with the corresponding material.

The command for Advanced mode may be repeated multiple times to tie different block types to different reinforcement materials. These associations last only until the player exits Advanced mode.

group is the NameLayer group the corresponding block type will be reinforced to. If not supplied, it will use the player's default group.

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. While in Normal mode, reinforcements cannot be created.

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.

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 (here 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 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

On CivMC, decay follows https://www.desmos.com/calculator/awern3k4ol, where the y axis is the multiplier and the x axis is the time passed in months.

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

Category	Command	Description	Alias
Info	/help citadel [page]	Lists all Citadel commands.	—
	/ctdl	Shows an interface of all reinforcement materials.	—
Reinforcement Modes	/ctf [group]	Enters fortify mode.	/ctfortify
	/ctr [group]	Enters reinforce mode.	/ctreinforce
	/cta [group]	Enters advanced mode.	/ctadvanced
	/cto	Enters normal mode.	/ctoff
	/cte [group]	Enters easy mode.	/cteasy
Toggle Modes	/cti	Toggles info mode.	/ctinfo
	/ctb	Toggles bypass mode.	/ctbypass
	/ctin	Toggles insecure mode.	/ctinsecure
Acid Block	/ctacid	Activates an acid block.	—

History

CivMC
July 16, 2023	Acid maturation durations changed for Stone (2 hours -> 30 minutes), Iron Ingot (12 hours -> 6 hours), Nether Brick (2 hours -> 30 minutes), and Gold Ingot (12 hours -> 6 hours)
April 5, 2023	Maturation durations changed for Stone (5 minutes -> 30 minutes), Iron Ingot (30 minutes -> 4 hours), Diamond (4 hours -> 12 hours), Nether Brick (5 minutes -> 30 minutes), Gold Ingot (30 minutes -> 4 hours), and Gilded Blackstone (4 hours -> 12 hours). Acid maturation durations changed for Stone (20 minutes -> 2 hours), Iron Ingot (6 hours -> 12 hours), Diamond (2 days -> 1 day), Nether Brick (20 minutes -> 2 hours), Gold Ingot (6 hours -> 12 hours), and Gilded Blackstone (2 days -> 1 day).
September 19, 2022	Diamond and Netherite blocks are added as acid blocks, which apply acid vertically and in all directions respectively. Gold blocks still only apply acid upwards.
June 2, 2022	Server launches with Citadel.
CivClassic 2.0
June 2, 2017	Server launches with Citadel.
Devoted 3.0
September 17, 2016	Server launches with Citadel.
Civcraft 3.0
July 30, 2016	Server launches with Citadel.
Civcraft 2.0
May 19, 2013	Server launches with Citadel.
Civcraft 1.0
March 24, 2012	Server launches with Citadel.