diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..a4335df
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,3 @@
+# Keep CRLF for *.bat files which are for Windows.
+# Ref: https://stackoverflow.com/questions/21822650
+*.bat -crlf
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
new file mode 100644
index 0000000..0581c91
--- /dev/null
+++ b/.github/workflows/release.yml
@@ -0,0 +1,68 @@
+name: release
+on:
+  push:
+    tags:
+      - "**"
+jobs:
+  publish:
+    runs-on: ubuntu-18.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          # Fetch all history 
+          fetch-depth: 0
+      - name: Maven Publish
+        id: maven_publish
+        env:
+          MAVEN_USERNAME: ${{ secrets.TEACON_USERNAME }}
+          MAVEN_PASSWORD: ${{ secrets.TEACON_PASSWORD }}
+        run: ./gradlew publishReleasePublicationToArchiveRepository githubActionOutput
+      - name: Generate Changelog
+        id: changelog
+        shell: bash
+        env:
+          CURRENT: ${{ github.ref }}
+        # Special thanks to this post on Stack Overflow regarding change set between two tags:
+        # https://stackoverflow.com/questions/12082981
+        # Do note that actions/checkout will enter detach mode by default, so you won't have 
+        # access to HEAD ref. Use GitHub-Action-supplied `github.ref` instead.
+        # Special thanks to this issue ticket regarding escaping newline:
+        # https://github.com/actions/create-release/issues/25
+        # We use Bash parameter expansion to do find-and-replace.
+        # https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html
+        # Also we cannot use git rev-list because it always prepend "commit <hash>"
+        # See https://stackoverflow.com/questions/36927089/
+        run: |
+          current_tag=${CURRENT/refs\/tags\//}
+          last_tag=`git describe --tags --abbrev=0 "$current_tag"^ 2>/dev/null || echo`
+          if [ last_tag ]; then
+          changelog=`git log --pretty="format:%H: %s" ${last_tag}..$current_tag`
+          else
+          changelog=`git log --pretty="format:%H: %s"`
+          fi
+          changelog="${changelog//'%'/'%25'}"
+          changelog="${changelog//$'\n'/'  %0A'}"
+          echo "::set-output name=value::Change set since ${last_tag:-the beginning}:  %0A%0A$changelog"
+      - name: GitHub Release
+        id: create_release
+        uses: actions/create-release@v1.1.1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: ${{ github.ref }}
+          draft: false
+          prerelease: false
+          body: |
+            ${{ steps.changelog.outputs.value }}
+      - name: GitHub Release Artifact
+        uses: actions/upload-release-asset@v1.0.2
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }}
+          asset_path: ${{ steps.maven_publish.outputs.artifact_path }}
+          asset_name: ${{ steps.maven_publish.outputs.artifact_name }}
+          # https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types
+          asset_content_type: "application/java-archive"
diff --git a/.github/workflows/test-build.yml b/.github/workflows/test-build.yml
new file mode 100644
index 0000000..22e3407
--- /dev/null
+++ b/.github/workflows/test-build.yml
@@ -0,0 +1,14 @@
+name: test-build
+on:
+  push:
+    paths:
+      - "src/**"
+      - "build.gradle"
+jobs:
+  build:
+    runs-on: ubuntu-18.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Build
+        run: ./gradlew build --stacktrace
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..757f761
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,27 @@
+# eclipse
+bin
+*.launch
+.settings
+.metadata
+.classpath
+.project
+
+# idea
+out
+*.ipr
+*.iws
+*.iml
+.idea
+
+# vscode
+.vscode
+
+# gradle
+build
+.gradle
+
+# other
+eclipse
+run
+*.txt
+
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..b67a13d
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,24 @@
+Copyright (c) 2020, TeaConMC members and contributors
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+    * Neither the name of the TeaConMC nor the
+      names of its contributors may be used to endorse or promote products
+      derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL TEACONMC MEMBERS AND CONTRIBUTORS BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
\ No newline at end of file
diff --git a/build.gradle b/build.gradle
new file mode 100644
index 0000000..692ef01
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,149 @@
+import java.time.Instant
+import java.time.format.DateTimeFormatter
+import java.time.temporal.ChronoUnit
+
+buildscript {
+    repositories {
+        maven { url = 'https://files.minecraftforge.net/maven' }
+        jcenter()
+        mavenCentral()
+    }
+    dependencies {
+        classpath group: 'net.minecraftforge.gradle', name: 'ForgeGradle', version: '3.+', changing: true
+    }
+}
+apply plugin: 'net.minecraftforge.gradle'
+apply plugin: 'eclipse'
+apply plugin: 'maven-publish'
+
+version = '0.1.0'
+group = 'org.teacon'
+archivesBaseName = 'AreaControl-Forge-1.15'
+
+sourceCompatibility = targetCompatibility = compileJava.sourceCompatibility = compileJava.targetCompatibility = '1.8'
+
+minecraft {
+    mappings channel: 'snapshot', version: '20200513-1.15.1'
+    
+    runs {
+        client {
+            workingDirectory project.file('run')
+            property 'forge.logging.console.level', 'info'
+            mods {
+                area_control {
+                    source sourceSets.main
+                }
+            }
+        }
+
+        server {
+            workingDirectory project.file('run_server')
+            property 'forge.logging.console.level', 'info'
+            mods {
+                area_control {
+                    source sourceSets.main
+                }
+            }
+        }
+
+        data {
+            workingDirectory project.file('run')
+            property 'forge.logging.console.level', 'info'
+            args '--mod', 'area_control', '--all', '--output', file('src/generated/resources/')
+            mods {
+                area_control {
+                    source sourceSets.main
+                }
+            }
+        }
+    }
+}
+
+dependencies {
+    minecraft 'net.minecraftforge:forge:1.15.2-31.2.4'
+}
+
+jar {
+    manifest {
+        attributes([
+            "Specification-Title": "Area-Control",
+            "Specification-Vendor": "TeaConMC",
+            "Specification-Version": "1",
+            "Implementation-Title": project.name,
+            "Implementation-Version": "${version}",
+            "Implementation-Vendor": "TeaConMC",
+            "Implementation-Timestamp": DateTimeFormatter.ISO_INSTANT.format(Instant.now().truncatedTo(ChronoUnit.SECONDS))
+        ])
+    }
+}
+
+def reobfFile = file("$buildDir/reobfJar/output.jar")
+def reobfArtifact = artifacts.add('default', reobfFile) {
+    type 'jar'
+    builtBy 'reobfJar'
+}
+publishing {
+    publications {
+        release(MavenPublication) {
+            groupId = "org.teacon"
+            artifactId = "AreaControl-Forge-1.15"
+
+            artifact reobfArtifact
+            pom {
+                name = 'AreaControl for Minecraft 1.15'
+                description = 'Comprehensive (maybe) plot management mod'
+                url = 'https://github.com/teaconmc/AreaControl'
+                licenses {
+                    license {
+                        name = 'BSD-3-Clause'
+                        url = 'https://github.com/teaconmc/AreaControl/blob/1.15-forge/LICENSE'
+                    }
+                }
+                developers {
+                    developer {
+                        id = '3TUSK'
+                        name = '3TUSK'
+                    }
+                }
+                issueManagement {
+                    system = 'GitHub Issues'
+                    url = 'https://github.com/teaconmc/AreaControl/issues'
+                }
+                scm {
+                    url = 'https://github.com/teaconmc/AreaControl'
+                    connection = 'scm:git:git://github.com/teaconmc/AreaControl.git'
+                    developerConnection = 'scm:git:git@github.com:teaconmc/AreaControl.git'
+                }
+            }
+        }
+    }
+    repositories {
+        maven {
+            name = "archive"
+            url = "https://maven.hub.tritusk.info/releases"
+            credentials {
+                username = System.env.MAVEN_USERNAME
+                password = System.env.MAVEN_PASSWORD
+            }
+        }
+    }
+}
+
+tasks.withType(PublishToMavenRepository) {
+    onlyIf {
+        System.env.MAVEN_USERNAME && System.env.MAVEN_PASSWORD
+    }
+}
+
+/**
+ * A simple task to pass down the artifact name and path to other GitHub actions.
+ */
+task("githubActionOutput") {
+    onlyIf {
+        System.env.GITHUB_ACTIONS
+    }
+    doLast {
+        println "::set-output name=artifact_path::$buildDir/reobfJar/output.jar"
+        println "::set-output name=artifact_name::$archivesBaseName-${version}.jar"
+    }
+}
diff --git a/gradle.properties b/gradle.properties
new file mode 100644
index 0000000..c4f1c9e
--- /dev/null
+++ b/gradle.properties
@@ -0,0 +1,4 @@
+# Ensure enough heap space during deployment
+org.gradle.jvmargs=-Xmx3G
+# It is said that daemon often brings more issues, so we disable it.
+org.gradle.daemon=false
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..7a3265e
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..949819d
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.9-bin.zip
diff --git a/gradlew b/gradlew
new file mode 100755
index 0000000..cccdd3d
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 0000000..e95643d
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/src/main/java/org/teacon/areacontrol/AreaControl.java b/src/main/java/org/teacon/areacontrol/AreaControl.java
new file mode 100644
index 0000000..014e118
--- /dev/null
+++ b/src/main/java/org/teacon/areacontrol/AreaControl.java
@@ -0,0 +1,68 @@
+package org.teacon.areacontrol;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import org.apache.commons.lang3.tuple.Pair;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import net.minecraft.server.MinecraftServer;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.ExtensionPoint;
+import net.minecraftforge.fml.ModLoadingContext;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.event.server.FMLServerStartingEvent;
+import net.minecraftforge.fml.event.server.FMLServerStoppingEvent;
+import net.minecraftforge.fml.network.FMLNetworkConstants;
+
+@Mod("area_control")
+@Mod.EventBusSubscriber(modid = "area_control")
+public final class AreaControl {
+
+    private static final Logger LOGGER = LogManager.getLogger("AreaControl");
+
+    public AreaControl() {
+        ModLoadingContext context = ModLoadingContext.get();
+        context.registerExtensionPoint(ExtensionPoint.DISPLAYTEST,
+                () -> Pair.of(() -> FMLNetworkConstants.IGNORESERVERONLY, (serverVer, isDedi) -> true));
+    }
+
+    @SubscribeEvent
+    public static void onServerStart(FMLServerStartingEvent event) {
+        // Remember, when update Forge, make sure to use the command register event
+        // PR-ed by jaredlll08
+        new AreaControlCommand(event.getCommandDispatcher());
+
+        final MinecraftServer server = event.getServer();
+        final Path dataDir = server.getActiveAnvilConverter().getFile(server.getFolderName(), "serverconfig").toPath()
+                .resolve("area_control");
+        if (Files.isDirectory(dataDir)) {
+            try {
+                AreaManager.INSTANCE.loadFrom(dataDir);
+            } catch (Exception e) {
+                LOGGER.error("Failed to read claims data, details: {}", e);
+            }
+        } else {
+            try {
+                Files.createDirectories(dataDir);
+            } catch (Exception e) {
+                LOGGER.warn("Failed to create data directory. Details: {}", e);
+            }
+        }
+    }
+
+    @SubscribeEvent
+    public static void onServerStop(FMLServerStoppingEvent event) {
+        final MinecraftServer server = event.getServer();
+        final Path dataDir = server.getActiveAnvilConverter().getFile(server.getFolderName(), "serverconfig").toPath()
+                .resolve("area_control");
+        if (Files.isDirectory(dataDir)) {
+            try {
+                AreaManager.INSTANCE.saveTo(dataDir);
+            } catch (Exception e) {
+                LOGGER.warn("Failed to create data directory. Details: {}", e);
+            }
+        } 
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/org/teacon/areacontrol/AreaControlClaimHandler.java b/src/main/java/org/teacon/areacontrol/AreaControlClaimHandler.java
new file mode 100644
index 0000000..1d21aa0
--- /dev/null
+++ b/src/main/java/org/teacon/areacontrol/AreaControlClaimHandler.java
@@ -0,0 +1,39 @@
+package org.teacon.areacontrol;
+
+import java.util.ArrayDeque;
+import java.util.WeakHashMap;
+
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.item.Item;
+import net.minecraft.item.Items;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.text.StringTextComponent;
+import net.minecraftforge.event.entity.player.PlayerInteractEvent;
+import net.minecraftforge.eventbus.api.EventPriority;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.LogicalSide;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.server.permission.PermissionAPI;
+
+@Mod.EventBusSubscriber(modid = "area_control")
+public final class AreaControlClaimHandler {
+
+    static Item userClaimTool = Items.STICK;
+    static Item adminTool = Items.TRIDENT;
+
+    static WeakHashMap<PlayerEntity, ArrayDeque<BlockPos>> recordPos = new WeakHashMap<>();
+
+    @SubscribeEvent(priority = EventPriority.LOWEST)
+    public static void onRightClick(PlayerInteractEvent.RightClickBlock event) {
+        if (event.getSide() == LogicalSide.SERVER) {
+            final PlayerEntity player = event.getPlayer();
+            if (event.getItemStack().getItem() == adminTool && PermissionAPI.hasPermission(player, "area_control.admin.inspect")) {
+                player.sendStatusMessage(new StringTextComponent("AreaControl: Welcome back, administrator"), true);
+            } else if (event.getItemStack().getItem() == userClaimTool) {
+                final BlockPos clicked;
+                recordPos.computeIfAbsent(player, p -> new ArrayDeque<>()).offerLast(clicked = event.getPos().toImmutable());
+                player.sendStatusMessage(new StringTextComponent(String.format("AreaControl: Marked position x=%d, y=%d, z=%d ", clicked.getX(), clicked.getY(), clicked.getZ())), true);
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/org/teacon/areacontrol/AreaControlCommand.java b/src/main/java/org/teacon/areacontrol/AreaControlCommand.java
new file mode 100644
index 0000000..986976e
--- /dev/null
+++ b/src/main/java/org/teacon/areacontrol/AreaControlCommand.java
@@ -0,0 +1,90 @@
+package org.teacon.areacontrol;
+
+import java.util.ArrayDeque;
+
+import com.mojang.brigadier.Command;
+import com.mojang.brigadier.CommandDispatcher;
+import com.mojang.brigadier.arguments.StringArgumentType;
+import com.mojang.brigadier.context.CommandContext;
+import com.mojang.brigadier.exceptions.CommandSyntaxException;
+
+import org.teacon.areacontrol.api.Area;
+
+import net.minecraft.command.CommandSource;
+import net.minecraft.command.Commands;
+import net.minecraft.util.math.AxisAlignedBB;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.text.StringTextComponent;
+
+public final class AreaControlCommand {
+
+    public AreaControlCommand(CommandDispatcher<CommandSource> dispatcher) {
+        dispatcher.register(Commands.literal("ac")
+                .redirect(dispatcher.register(Commands.literal("areacontrol")
+                        .then(Commands.literal("about").executes(AreaControlCommand::about))
+                        .then(Commands.literal("admin").executes(AreaControlCommand::admin))
+                        .then(Commands.literal("claim").executes(AreaControlCommand::claim))
+                        .then(Commands.literal("list").executes(AreaControlCommand::list))
+                        .then(Commands.literal("set").then(
+                            Commands.argument("property", StringArgumentType.string()).then(
+                                Commands.argument("value", StringArgumentType.greedyString())
+                                    .executes(AreaControlCommand::setProperty)
+                            )))
+                        )
+                )
+        );
+    }
+
+    private static int about(CommandContext<CommandSource> context) {
+        context.getSource().sendFeedback(new StringTextComponent("AreaControl 0.1.0"), false);
+        return Command.SINGLE_SUCCESS;
+    }
+
+    private static int admin(CommandContext<CommandSource> context) {
+        context.getSource().sendFeedback(new StringTextComponent("WIP"), false);
+        return Command.SINGLE_SUCCESS;
+    }
+
+    private static int claim(CommandContext<CommandSource> context) throws CommandSyntaxException {
+        final CommandSource src = context.getSource();
+        final ArrayDeque<BlockPos> recordPos = AreaControlClaimHandler.recordPos.get(src.asPlayer());
+        if (recordPos != null && recordPos.size() >= 2) {
+            final Area area = Util.createArea("Unnamed area " + Util.nextRandomString(), new AxisAlignedBB(recordPos.pop(), recordPos.pop()));
+            recordPos.clear();
+            if (AreaManager.INSTANCE.add(area)) {
+                src.sendFeedback(new StringTextComponent(String.format("Claim '%s' has been created from [%d, %d, %d] to [%d, %d, %d]", area.name, area.minX, area.minY, area.minZ, area.maxX, area.maxY, area.maxZ)), true);
+                return Command.SINGLE_SUCCESS;
+            } else {
+                src.sendFeedback(new StringTextComponent("Cannot claim the selected area because it overlaps another claimed area. Perhaps try somewhere else?"), false);
+                return -2;
+            }
+        } else {
+            src.sendFeedback(new StringTextComponent("Cannot determine what area you want to claim. Did you forget to select an area?"), false);
+            return -1;
+        }
+        
+    }
+
+    private static int list(CommandContext<CommandSource> context) throws CommandSyntaxException {
+        final CommandSource src = context.getSource();
+        src.sendFeedback(new StringTextComponent("Currently known areas: "), false);
+        for (Area a : AreaManager.INSTANCE.getKnownAreas()) {
+            src.sendFeedback(new StringTextComponent(String.format("  - %s (from [%d, %d, %d] to [%d, %d, %d])", a.name, a.minX, a.minY, a.minZ, a.maxX, a.maxY, a.maxZ)), false);
+        }
+        return Command.SINGLE_SUCCESS;
+    }
+
+    private static int setProperty(CommandContext<CommandSource> context) throws CommandSyntaxException {
+        final Area area = AreaManager.INSTANCE.findBy(new BlockPos(context.getSource().getPos()));
+        if (area != AreaManager.INSTANCE.wildness) {
+            final String prop = context.getArgument("property", String.class);
+            final String value = context.getArgument("value", String.class);
+            area.properties.put(prop, value);
+            context.getSource().sendFeedback(new StringTextComponent(String.format("Area '%s''s property '%s' has been updated to '%s'", area.name, prop, value)), true);
+            return Command.SINGLE_SUCCESS;
+        } else {
+            context.getSource().sendErrorMessage(new StringTextComponent("You are in the wildness. What were you thinking?"));
+            return -1;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/org/teacon/areacontrol/AreaControlEventHandlers.java b/src/main/java/org/teacon/areacontrol/AreaControlEventHandlers.java
new file mode 100644
index 0000000..0cf30d6
--- /dev/null
+++ b/src/main/java/org/teacon/areacontrol/AreaControlEventHandlers.java
@@ -0,0 +1,97 @@
+package org.teacon.areacontrol;
+
+import org.teacon.areacontrol.api.Area;
+import org.teacon.areacontrol.api.AreaProperties;
+
+import net.minecraft.util.math.BlockPos;
+import net.minecraftforge.event.entity.living.LivingSpawnEvent;
+import net.minecraftforge.event.entity.player.PlayerInteractEvent;
+import net.minecraftforge.event.world.BlockEvent;
+import net.minecraftforge.event.world.ExplosionEvent;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.eventbus.api.Event;
+import net.minecraftforge.eventbus.api.EventPriority;
+import net.minecraftforge.fml.common.Mod;
+
+@Mod.EventBusSubscriber(modid = "area_control")
+public final class AreaControlEventHandlers {
+    @SubscribeEvent(priority = EventPriority.HIGHEST)
+    public static void onCheckSpawn(LivingSpawnEvent.CheckSpawn event) {
+        final BlockPos spawnPos = new BlockPos(event.getX(), event.getY(), event.getZ());
+        final Area targetArea = AreaManager.INSTANCE.findBy(spawnPos);
+        if (targetArea != null && !AreaProperties.getBool(targetArea, "area.allow_spawn")) {
+            event.setResult(Event.Result.DENY);
+        }
+    }
+
+    @SubscribeEvent(priority = EventPriority.HIGHEST)
+    public static void onSpecialSpawn(LivingSpawnEvent.SpecialSpawn event) {
+        final BlockPos spawnPos = new BlockPos(event.getX(), event.getY(), event.getZ());
+        final Area targetArea = AreaManager.INSTANCE.findBy(spawnPos);
+        if (targetArea != null && !AreaProperties.getBool(targetArea, "area.allow_special_spawn")) {
+            event.setCanceled(true);
+        }
+    }
+
+    @SubscribeEvent(priority = EventPriority.HIGHEST)
+    public static void onBreakBlock(BlockEvent.BreakEvent event) {
+        final Area targetArea = AreaManager.INSTANCE.findBy(event.getPos());
+        if (targetArea != null && !AreaProperties.getBool(targetArea, "area.allow_break_block")) {
+            event.setCanceled(true);
+        }
+    }
+
+    @SubscribeEvent(priority = EventPriority.HIGHEST)
+    public static void onClickBlock(PlayerInteractEvent.LeftClickBlock event) {
+        final Area targetArea = AreaManager.INSTANCE.findBy(event.getPos());
+        if (targetArea != null && !AreaProperties.getBool(targetArea, "area.allow_click_block")) {
+            event.setCanceled(true);
+        }
+    }
+
+    @SubscribeEvent(priority = EventPriority.HIGHEST)
+    public static void onActivateBlock(PlayerInteractEvent.RightClickBlock event) {
+        final Area targetArea = AreaManager.INSTANCE.findBy(event.getPos());
+        if (targetArea != null && !AreaProperties.getBool(targetArea, "area.allow_activate_block")) {
+            event.setCanceled(true);
+        }
+    }
+
+    @SubscribeEvent(priority = EventPriority.HIGHEST)
+    public static void onUseItem(PlayerInteractEvent.RightClickItem event) {
+        final Area targetArea = AreaManager.INSTANCE.findBy(event.getPos());
+        if (targetArea != null && !AreaProperties.getBool(targetArea, "area.allow_use_item")) {
+            event.setCanceled(true);
+        }
+    }
+
+    @SubscribeEvent(priority = EventPriority.HIGHEST)
+    public static void onPlaceBlock(BlockEvent.EntityPlaceEvent event) {
+        final Area targetArea = AreaManager.INSTANCE.findBy(event.getPos());
+        if (targetArea != null && !AreaProperties.getBool(targetArea, "area.allow_place_block")) {
+            // TODO Does this consume the item?
+            event.setCanceled(true);
+        }
+    }
+
+    @SubscribeEvent(priority = EventPriority.HIGHEST)
+    public static void beforeExplosion(ExplosionEvent.Start event) {
+        final Area targetArea = AreaManager.INSTANCE.findBy(new BlockPos(event.getExplosion().getPosition()));
+        if (targetArea != null && !AreaProperties.getBool(targetArea, "area.allow_explosion")) {
+            event.setCanceled(true);
+        }
+    }
+
+    @SubscribeEvent(priority = EventPriority.HIGHEST)
+    public static void afterExplosion(ExplosionEvent.Detonate event) {
+        final Area targetArea = AreaManager.INSTANCE.findBy(new BlockPos(event.getExplosion().getPosition()));
+        if (targetArea != null) {
+            if (!AreaProperties.getBool(targetArea, "area.allow_explosion_affect_blocks")) {
+                event.getAffectedBlocks().clear();
+            }
+            if (!AreaProperties.getBool(targetArea, "area.allow_explosion_affect_entities")) {
+                event.getAffectedEntities().clear();
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/org/teacon/areacontrol/AreaManager.java b/src/main/java/org/teacon/areacontrol/AreaManager.java
new file mode 100644
index 0000000..9ceee73
--- /dev/null
+++ b/src/main/java/org/teacon/areacontrol/AreaManager.java
@@ -0,0 +1,128 @@
+package org.teacon.areacontrol;
+
+import java.io.Reader;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+
+import org.teacon.areacontrol.api.Area;
+
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.ChunkPos;
+
+public final class AreaManager {
+
+    public static final AreaManager INSTANCE = new AreaManager();
+
+    private static final Gson GSON = new GsonBuilder().setPrettyPrinting().create();
+    
+    final Area wildness = new Area();
+
+    private final HashMap<String, Area> areasByName = new HashMap<>();
+    /**
+     * All known instances of {@link Area}, indexed by chunk positions covered by this area. 
+     * Used for faster lookup of {@link Area}.
+     */
+    private final HashMap<ChunkPos, List<Area>> areasByChunk = new HashMap<>();
+
+    {
+        wildness.name = "wildness";
+        wildness.minX = Integer.MIN_VALUE;
+        wildness.minY = Integer.MIN_VALUE;
+        wildness.minZ = Integer.MIN_VALUE;
+        wildness.maxX = Integer.MAX_VALUE;
+        wildness.maxY = Integer.MAX_VALUE;
+        wildness.maxZ = Integer.MAX_VALUE;
+        wildness.properties.put("area.allow_click_block", true);
+        wildness.properties.put("area.allow_activate_block", true);
+        wildness.properties.put("area.allow_use_item", true);
+    }
+
+    private void buildCacheFor(Area area) {
+        ChunkPos.getAllInBox(new ChunkPos(area.minX >> 4, area.minZ >> 4), new ChunkPos(area.maxX >> 4, area.maxZ >> 4))
+                .map(cp -> this.areasByChunk.computeIfAbsent(cp, _cp -> new ArrayList<>()))
+                .forEach(list -> list.add(area));
+    }
+
+    void loadFrom(Path dataDirRoot) throws Exception {
+        Path userDefinedAreas = dataDirRoot.resolve("claims.json");
+        if (Files.isRegularFile(userDefinedAreas)) {
+            try (Reader reader = Files.newBufferedReader(userDefinedAreas)) {
+                for (Area a : GSON.fromJson(reader, Area[].class)) {
+                    areasByName.put(a.name, a);
+                }
+            }
+        }
+        Path wildnessArea = dataDirRoot.resolve("wildness.json");
+        if (Files.isRegularFile(wildnessArea)) {
+            try (Reader reader = Files.newBufferedReader(userDefinedAreas)) {
+                Area a = GSON.fromJson(reader, Area.class);
+                this.wildness.properties.putAll(a.properties);
+            }
+        }
+    }
+
+    void saveTo(Path dataDirRoot) throws Exception {
+        Path userDefinedAreas = dataDirRoot.resolve("claims.json");
+        Files.write(userDefinedAreas, GSON.toJson(this.areasByName.values()).getBytes(StandardCharsets.UTF_8));
+        Path wildnessArea = dataDirRoot.resolve("wildness.json");
+        Files.write(wildnessArea, GSON.toJson(this.wildness).getBytes(StandardCharsets.UTF_8));
+    }
+
+    /**
+     * @param area The Area instance to be recorded
+     * @return true if and only if the area is successfully recorded by this AreaManager; false otherwise.
+     */
+    public boolean add(Area area) {
+        // First we filter out cases where at least one defining coordinate falls in an existing area
+        if (findBy(new BlockPos(area.minX, 0, area.minZ)) == this.wildness && findBy(new BlockPos(area.maxX, 0, area.maxZ)) == this.wildness) {
+            // Second we filter out cases where the area to define is enclosing another area.
+            boolean noEnclosing = true;
+            for (Area a : areasByName.values()) {
+                if (area.minX < a.minX && a.maxX < area.maxX) {
+                    if (area.minY < a.minY && a.maxY < area.maxY) {
+                        if (area.minZ < a.minZ && a.maxZ < area.maxZ) {
+                            noEnclosing = false;
+                            break;
+                        }
+                    }
+                }
+            }
+            if (noEnclosing) {
+                areasByName.computeIfAbsent(area.name, name -> area);
+                this.buildCacheFor(area);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public Area findBy(BlockPos pos) {
+        for (Area area : this.areasByChunk.getOrDefault(new ChunkPos(pos), Collections.emptyList())) {
+            if (area.minX <= pos.getX() && pos.getX() <= area.maxX) {
+                if (area.minY <= pos.getY() && pos.getY() <= area.maxY) {
+                    if (area.minZ <= pos.getZ() && pos.getZ() <= area.maxZ) {
+                        return area;
+                    }
+                }
+            }
+        }
+        return wildness;
+    }
+
+    public Area findBy(String name) {
+        return areasByName.get(name);
+    }
+
+    public Collection<Area> getKnownAreas() {
+		return Collections.unmodifiableCollection(this.areasByName.values());
+	}
+}
\ No newline at end of file
diff --git a/src/main/java/org/teacon/areacontrol/Util.java b/src/main/java/org/teacon/areacontrol/Util.java
new file mode 100644
index 0000000..69f6be2
--- /dev/null
+++ b/src/main/java/org/teacon/areacontrol/Util.java
@@ -0,0 +1,36 @@
+package org.teacon.areacontrol;
+
+import java.util.Random;
+
+import org.teacon.areacontrol.api.Area;
+
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.util.math.AxisAlignedBB;
+
+public final class Util {
+
+    private static final Random RAND = new Random();
+
+    public static String nextRandomString() {
+        // https://stackoverflow.com/questions/14622622/generating-a-random-hex-string-of-length-50-in-java-me-j2me#comment100639373_14623245
+        // tldr: formatting to 8 digits of hexadecimal number, padding zeros at beginning
+        return String.format("%08x", RAND.nextInt());
+    }
+
+    public static boolean isOpInServer(PlayerEntity player, MinecraftServer server) {
+        return server.getPlayerList().getOppedPlayers().getEntry(player.getGameProfile()) != null;
+    }
+
+	public static Area createArea(String name, AxisAlignedBB box) {
+        final Area a = new Area();
+        a.name = name;
+        a.minX = (int) box.minX;
+        a.minY = (int) box.minY;
+        a.minZ = (int) box.minZ;
+        a.maxX = (int) box.maxX;
+        a.maxY = (int) box.maxY;
+        a.maxZ = (int) box.maxZ;
+		return a;
+	}
+}
\ No newline at end of file
diff --git a/src/main/java/org/teacon/areacontrol/api/Area.java b/src/main/java/org/teacon/areacontrol/api/Area.java
new file mode 100644
index 0000000..1b16c90
--- /dev/null
+++ b/src/main/java/org/teacon/areacontrol/api/Area.java
@@ -0,0 +1,16 @@
+package org.teacon.areacontrol.api;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * A cuboid area defined by min. coordinate and max. coordinate.
+ */
+public final class Area {
+
+    public String name;
+
+    public int minX, minY, minZ, maxX, maxY, maxZ;
+
+    public final Map<String, Object> properties = new HashMap<>();
+}
\ No newline at end of file
diff --git a/src/main/java/org/teacon/areacontrol/api/AreaProperties.java b/src/main/java/org/teacon/areacontrol/api/AreaProperties.java
new file mode 100644
index 0000000..5c6c79c
--- /dev/null
+++ b/src/main/java/org/teacon/areacontrol/api/AreaProperties.java
@@ -0,0 +1,44 @@
+package org.teacon.areacontrol.api;
+
+public final class AreaProperties {
+    private AreaProperties() {}
+
+    public static boolean getBool(Area area, String key) {
+        Object o = area.properties.get(key);
+        if (o == null) {
+            return false;
+        } else if (o instanceof Boolean) {
+            return (Boolean) o;
+        } else if (o instanceof Number) {
+            return ((Number) o).intValue() != 0;
+        } else {
+            return "true".equals(o) || "t".equals(o) || Character.valueOf('t').equals(o);
+        }
+    }
+
+    public static int getInt(Area area, String key) {
+        Object o = area.properties.get(key);
+        if (o == null) {
+            return 0;
+        } else if (o instanceof Number) {
+            return ((Number) o).intValue();
+        } else {
+            return o instanceof Boolean ? (Boolean) o ? 1 : 0 : 0;
+        }
+    }
+
+    public static double getDouble(Area area, String key) {
+        Object o = area.properties.get(key);
+        if (o == null) {
+            return 0.0;
+        } else if (o instanceof Number) {
+            return ((Number) o).doubleValue();
+        } else {
+            return o instanceof Boolean ? (Boolean) o ? 1.0 : 0.0 : 0.0;
+        }
+    }
+    
+    public static String getString(Area area, String key) {
+        return area.properties.getOrDefault(key, "").toString();
+    }
+}
\ No newline at end of file
diff --git a/src/main/resources/META-INF/mods.toml b/src/main/resources/META-INF/mods.toml
new file mode 100644
index 0000000..e042a8e
--- /dev/null
+++ b/src/main/resources/META-INF/mods.toml
@@ -0,0 +1,15 @@
+modLoader="javafml"
+
+loaderVersion="[31,)"
+
+[[mods]]
+modId="area_control"
+version="${file.jarVersion}"
+displayName="Area Control"
+
+# We will come back later.
+credits=""
+
+authors="3TUSK"
+
+description="A comprehensive (maybe) plot management mod under Forge framework."
\ No newline at end of file
diff --git a/src/main/resources/pack.mcmeta b/src/main/resources/pack.mcmeta
new file mode 100644
index 0000000..dbabbba
--- /dev/null
+++ b/src/main/resources/pack.mcmeta
@@ -0,0 +1 @@
+{"pack":{"pack_format":5,"description":"Things used by AreaControl mod"}}
\ No newline at end of file