diff --git a/logic/Preparation/GameData/GameData.cs b/logic/Preparation/GameData/GameData.cs
new file mode 100644
index 0000000..2d13d58
--- /dev/null
+++ b/logic/Preparation/GameData/GameData.cs
@@ -0,0 +1,77 @@
+using Preparation.Utility;
+
+namespace Preparation.GameData
+{
+    public static class GameData
+    {
+#region 基本常数与常方法
+        public const int numOfPosGridPerCell = 1000;  // 每格的【坐标单位】数
+        public const int numOfStepPerSecond = 20;     // 每秒行走的步数
+        public const int lengthOfMap = 50000;         // 地图长度
+        public const int rows = 50;                   // 行数
+        public const int cols = 50;                   // 列数
+        public const long gameDuration = 600000;      // 游戏时长600000ms = 10min
+        public const long frameDuration = 50;         // 每帧时长
+
+        public const int MinSpeed = 1;             // 最小速度
+        public const int MaxSpeed = int.MaxValue;  // 最大速度
+
+        public static XYPosition GetCellCenterPos(int x, int y)  // 求格子的中心坐标
+        {
+            XYPosition ret = new((x * numOfPosGridPerCell) + (numOfPosGridPerCell / 2), (y * numOfPosGridPerCell) + (numOfPosGridPerCell / 2));
+            return ret;
+        }
+        public static int PosGridToCellX(XYPosition pos)  // 求坐标所在的格子的x坐标
+        {
+            return pos.x / numOfPosGridPerCell;
+        }
+        public static int PosGridToCellY(XYPosition pos)  // 求坐标所在的格子的y坐标
+        {
+            return pos.y / numOfPosGridPerCell;
+        }
+        public static bool IsInTheSameCell(XYPosition pos1, XYPosition pos2)
+        {
+            return PosGridToCellX(pos1) == PosGridToCellX(pos2) && PosGridToCellY(pos1) == PosGridToCellY(pos2);
+        }
+#endregion
+#region 角色相关
+        /// <summary>
+        /// 玩家相关
+        /// </summary>
+        public const int characterRadius = numOfPosGridPerCell / 2;  // 人物半径
+        public const int basicAp = 3000;                             // 初始攻击力
+        public const int basicHp = 6000;                             // 初始血量
+        public const int basicCD = 3000;                             // 初始子弹冷却
+        public const int basicBulletNum = 3;                         // 基本初始子弹量
+        public const int MinAP = 0;                                  // 最小攻击力
+        public const int MaxAP = int.MaxValue;                       // 最大攻击力
+        public const double basicAttackRange = 9000;                 // 基本攻击范围
+        public const double basicBulletBombRange = 3000;             // 基本子弹爆炸范围
+        public const int basicMoveSpeed = 3000;                      // 基本移动速度，单位：s-1
+        public const int basicBulletMoveSpeed = 3000;                // 基本子弹移动速度，单位：s-1
+        public const int characterMaxSpeed = 12000;                  // 最大速度
+        public const int addScoreWhenKillOneLevelPlayer = 30;        // 击杀一级角色获得的加分
+        public const int commonSkillCD = 30000;                      // 普通技能标准冷却时间
+        public const int commonSkillTime = 10000;                    // 普通技能标准持续时间
+        public const int bulletRadius = 200;                         // 默认子弹半径
+        public const int reviveTime = 30000;                         // 复活时间
+        public const int shieldTimeAtBirth = 3000;                   // 复活时的护盾时间
+        public const int gemToScore = 4;                             // 一个宝石的标准加分
+        /// <summary>
+        /// 道具相关
+        /// </summary>
+        public const int MinPropTypeNum = 1;
+        public const int MaxPropTypeNum = 10;
+        public const int PropRadius = numOfPosGridPerCell / 2;
+        public const int PropMoveSpeed = 3000;
+        public const int PropMaxMoveDistance = 15 * numOfPosGridPerCell;
+        public const int MaxGemSize = 5;  // 随机生成的宝石最大size
+        public const long GemProduceTime = 10000;
+        public const long PropProduceTime = 10000;
+        public const int PropDuration = 10000;
+#endregion
+#region 游戏帧相关
+        public const long checkInterval = 50;  // 检查位置标志、补充子弹的帧时长
+#endregion
+    }
+}
diff --git a/logic/Preparation/Interface/ICharacter.cs b/logic/Preparation/Interface/ICharacter.cs
new file mode 100644
index 0000000..a708e00
--- /dev/null
+++ b/logic/Preparation/Interface/ICharacter.cs
@@ -0,0 +1,11 @@
+using System;
+using Preparation.Utility;
+
+namespace Preparation.Interface
+{
+    public interface ICharacter : IGameObj
+    {
+        public long TeamID { get; }
+        public int HP { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/logic/Preparation/Interface/IGameObj.cs b/logic/Preparation/Interface/IGameObj.cs
new file mode 100644
index 0000000..a32a1c5
--- /dev/null
+++ b/logic/Preparation/Interface/IGameObj.cs
@@ -0,0 +1,20 @@
+using Preparation.Utility;
+
+namespace Preparation.Interface
+{
+    public interface IGameObj
+    {
+        public GameObjType Type { get; set; }
+        public long ID { get; }
+        public XYPosition Position { get; }  // if Square, Pos equals the center
+        public double FacingDirection { get; }
+        public bool IsRigid { get; }
+        public ShapeType Shape { get; }
+        public bool CanMove { get; set; }
+        public bool IsMoving { get; set; }
+        public bool IsResetting { get; set; }  // reviving
+        public bool IsAvailable { get; }
+        public int Radius { get; }  // if Square, Radius equals half length of one side
+        public PlaceType Place { get; set; }
+    }
+}
diff --git a/logic/Preparation/Interface/IMap.cs b/logic/Preparation/Interface/IMap.cs
new file mode 100644
index 0000000..0d781b3
--- /dev/null
+++ b/logic/Preparation/Interface/IMap.cs
@@ -0,0 +1,18 @@
+using System.Collections.Generic;
+using System.Threading;
+using Preparation.Utility;
+
+namespace Preparation.Interface
+{
+    public interface IMap
+    {
+        ITimer Timer { get; }
+
+        // the two dicts must have same keys
+        Dictionary<GameObjIdx, IList<IGameObj>> GameObjDict { get; }
+        Dictionary<GameObjIdx, ReaderWriterLockSlim> GameObjLockDict { get; }
+
+        public bool IsOutOfBound(IGameObj obj);
+        public IOutOfBound GetOutOfBound(XYPosition pos);  // 返回新建的一个OutOfBound对象
+    }
+}
diff --git a/logic/Preparation/Interface/IMoveable.cs b/logic/Preparation/Interface/IMoveable.cs
new file mode 100644
index 0000000..bc16f5b
--- /dev/null
+++ b/logic/Preparation/Interface/IMoveable.cs
@@ -0,0 +1,37 @@
+using System;
+using Preparation.Utility;
+
+namespace Preparation.Interface
+{
+    public interface IMoveable : IGameObj
+    {
+        object MoveLock { get; }
+        public int MoveSpeed { get; }
+        public long Move(Vector moveVec);
+        protected bool IgnoreCollide(IGameObj targetObj);                     // 忽略碰撞，在具体类中实现
+        public bool WillCollideWith(IGameObj? targetObj, XYPosition nextPos)  // 检查下一位置是否会和目标物碰撞
+        {
+            if (targetObj == null)
+                return false;
+            // 会移动的只有子弹和人物，都是Circle
+            if (!targetObj.IsRigid || targetObj.ID == ID)
+                return false;
+            if (IgnoreCollide(targetObj))
+                return false;
+            if (targetObj.Shape == ShapeType.Circle)
+            {
+                return XYPosition.Distance(nextPos, targetObj.Position) < targetObj.Radius + Radius;
+            }
+            else  // Square
+            {
+                long deltaX = Math.Abs(nextPos.x - targetObj.Position.x), deltaY = Math.Abs(nextPos.y - targetObj.Position.y);
+                if (deltaX >= targetObj.Radius + Radius || deltaY >= targetObj.Radius + Radius)
+                    return false;
+                if (deltaX < targetObj.Radius || deltaY < targetObj.Radius)
+                    return true;
+                else
+                    return ((long)(deltaX - targetObj.Radius) * (deltaX - targetObj.Radius)) + ((long)(deltaY - targetObj.Radius) * (deltaY - targetObj.Radius)) <= (long)Radius * (long)Radius;
+            }
+        }
+    }
+}
diff --git a/logic/Preparation/Interface/IObjOfCharacter.cs b/logic/Preparation/Interface/IObjOfCharacter.cs
new file mode 100644
index 0000000..92c5e40
--- /dev/null
+++ b/logic/Preparation/Interface/IObjOfCharacter.cs
@@ -0,0 +1,9 @@
+using System;
+
+namespace Preparation.Interface
+{
+    public interface IObjOfCharacter : IGameObj
+    {
+        ICharacter? Parent { get; set; }
+    }
+}
diff --git a/logic/Preparation/Interface/ITimer.cs b/logic/Preparation/Interface/ITimer.cs
new file mode 100644
index 0000000..bdcdcbc
--- /dev/null
+++ b/logic/Preparation/Interface/ITimer.cs
@@ -0,0 +1,9 @@
+
+namespace Preparation.Interface
+{
+    public interface ITimer
+    {
+        bool IsGaming { get; }
+        public bool StartGame(int timeInMilliseconds);
+    }
+}
diff --git a/logic/Preparation/Utility/Debugger.cs b/logic/Preparation/Utility/Debugger.cs
new file mode 100644
index 0000000..282d9b3
--- /dev/null
+++ b/logic/Preparation/Utility/Debugger.cs
@@ -0,0 +1,14 @@
+using System;
+
+namespace Preparation.Utility
+{
+    public class Debugger
+    {
+        static public void Output(object current, string str)
+        {
+#if DEBUG
+            Console.WriteLine(current.GetType() + " " + current.ToString() + " " + str);
+#endif
+        }
+    }
+}
diff --git a/logic/Preparation/Utility/EnumType.cs b/logic/Preparation/Utility/EnumType.cs
new file mode 100644
index 0000000..5dfb8cc
--- /dev/null
+++ b/logic/Preparation/Utility/EnumType.cs
@@ -0,0 +1,96 @@
+
+namespace Preparation.Utility
+{
+    /// <summary>
+    /// 存放所有用到的枚举类型
+    /// </summary>
+    public enum GameObjType
+    {
+        Null = 0,
+        Character = 1,
+        Prop = 2,
+        PickedProp = 3,
+        Bullet = 4,
+        BombedBullet = 5,
+
+        Wall = 6,
+        Grass = 7,
+        Generator = 8,  // 发电机
+        BirthPoint = 9,
+        Exit = 10,
+        EmergencyExit = 11,
+        OutOfBoundBlock = 12,  // 范围外
+    }
+    public enum ShapeType
+    {
+        Null = 0,
+        Circle = 1,  // 子弹和人物为圆形，格子为方形
+        Square = 2
+    }
+    public enum PlaceType  // 位置标志，包括陆地（一般默认为陆地，如墙体等），草丛。游戏中每一帧都要刷新各个物体的该属性
+    {
+        Null = 0,
+        Land = 1,
+        Grass1 = 2,
+        Grass2 = 3,
+        Grass3 = 4,
+        Grass4 = 5,
+        Grass5 = 6,
+    }
+    public enum BulletType  // 子弹类型
+    {
+        Null = 0,
+        OrdinaryBullet = 1,  // 普通子弹
+        AtomBomb = 2,        // 原子弹
+        FastBullet = 3,      // 快速子弹
+        LineBullet = 4       // 直线子弹
+    }
+    public enum PropType  // 道具类型
+    {
+        Null = 0,
+        addSpeed = 1,
+        addLIFE = 2,
+        Shield = 3,
+        Spear = 4,
+        Gem = 5,  // 新增：宝石
+    }
+    public enum PassiveSkillType  // 被动技能
+    {
+        Null = 0,
+        RecoverAfterBattle = 1,
+        SpeedUpWhenLeavingGrass = 2,
+        Vampire = 3,
+        PSkill3 = 4,
+        PSkill4 = 5,
+        PSkill5 = 6
+    }
+    public enum ActiveSkillType  // 主动技能
+    {
+        Null = 0,
+        BecomeVampire = 1,
+        BecomeAssassin = 2,
+        NuclearWeapon = 3,
+        SuperFast = 4,
+        ASkill4 = 5,
+        ASkill5 = 6
+    }
+    public enum BuffType  // buff
+    {
+        Null = 0,
+        AddSpeed = 1,
+        AddLIFE = 2,
+        Shield = 3,
+        Spear = 4
+    }
+    public enum GameObjIdx
+    {
+        None = 0,
+        Player = 1,
+        Bullet = 2,
+        Prop = 3,
+        Gem = 4,
+        Map = 5,
+        BombedBullet = 6,
+        PickedProp = 7
+    }
+}
diff --git a/logic/Preparation/Utility/MapEncoder.cs b/logic/Preparation/Utility/MapEncoder.cs
new file mode 100644
index 0000000..d8e2c4e
--- /dev/null
+++ b/logic/Preparation/Utility/MapEncoder.cs
@@ -0,0 +1,17 @@
+using System;
+
+namespace Preparation.Utility
+{
+    public class MapEncoder
+    {
+        static public char Dec2Hex(int d)
+        {
+            return char.Parse(d.ToString("X"));
+        }
+        static public int Hex2Dec(char h)
+        {
+            string hexabet = "0123456789ABCDEF";
+            return hexabet.IndexOf(h);
+        }
+    }
+}
diff --git a/logic/Preparation/Utility/Tools.cs b/logic/Preparation/Utility/Tools.cs
new file mode 100644
index 0000000..78ee847
--- /dev/null
+++ b/logic/Preparation/Utility/Tools.cs
@@ -0,0 +1,20 @@
+using System;
+
+namespace Preparation.Utility
+{
+    public static class Tools
+    {
+        public static double CorrectAngle(double angle)  // 将幅角转化为主值0~2pi
+        {
+            if (double.IsNaN(angle) || double.IsInfinity(angle))
+            {
+                return 0.0;
+            }
+            while (angle < 0)
+                angle += 2 * Math.PI;
+            while (angle >= 2 * Math.PI)
+                angle -= 2 * Math.PI;
+            return angle;
+        }
+    }
+}
diff --git a/logic/Preparation/Utility/Vector.cs b/logic/Preparation/Utility/Vector.cs
new file mode 100644
index 0000000..50614f0
--- /dev/null
+++ b/logic/Preparation/Utility/Vector.cs
@@ -0,0 +1,57 @@
+using System;
+
+namespace Preparation.Utility
+{
+    public struct Vector
+    {
+        public double angle;
+        public double length;
+
+        public static XYPosition VectorToXY(Vector v)
+        {
+            return new XYPosition((int)(v.length * Math.Cos(v.angle)), (int)(v.length * Math.Sin(v.angle)));
+        }
+        public Vector2 ToVector2()
+        {
+            return new Vector2((int)(this.length * Math.Cos(this.angle)), (int)(this.length * Math.Sin(this.angle)));
+        }
+        public static Vector XYToVector(double x, double y)
+        {
+            return new Vector(Math.Atan2(y, x), Math.Sqrt((x * x) + (y * y)));
+        }
+        public Vector(double angle, double length)
+        {
+            if (length < 0)
+            {
+                angle += Math.PI;
+                length = -length;
+            }
+            this.angle = Tools.CorrectAngle(angle);
+            this.length = length;
+        }
+    }
+
+    public struct Vector2
+    {
+        public double x;
+        public double y;
+        public Vector2(double x, double y)
+        {
+            this.x = x;
+            this.y = y;
+        }
+
+        public static double operator*(Vector2 v1, Vector2 v2)
+        {
+            return (v1.x * v2.x) + (v1.y * v2.y);
+        }
+        public static Vector2 operator +(Vector2 v1, Vector2 v2)
+        {
+            return new Vector2(v1.x + v2.x, v1.y + v2.y);
+        }
+        public static Vector2 operator -(Vector2 v1, Vector2 v2)
+        {
+            return new Vector2(v1.x - v2.x, v1.y - v2.y);
+        }
+    }
+}
diff --git a/logic/Preparation/Utility/XYPosition.cs b/logic/Preparation/Utility/XYPosition.cs
new file mode 100644
index 0000000..55647ec
--- /dev/null
+++ b/logic/Preparation/Utility/XYPosition.cs
@@ -0,0 +1,49 @@
+using System;
+
+namespace Preparation.Utility
+{
+    public struct XYPosition
+    {
+        public int x;
+        public int y;
+        public XYPosition(int x, int y)
+        {
+            this.x = x;
+            this.y = y;
+        }
+        public override string ToString()
+        {
+            return "(" + x.ToString() + "," + y.ToString() + ")";
+        }
+        public static XYPosition operator +(XYPosition p1, XYPosition p2)
+        {
+            return new XYPosition(p1.x + p2.x, p1.y + p2.y);
+        }
+        public static XYPosition operator -(XYPosition p1, XYPosition p2)
+        {
+            return new XYPosition(p1.x - p2.x, p1.y - p2.y);
+        }
+        public static double Distance(XYPosition p1, XYPosition p2)
+        {
+            return Math.Sqrt(((long)(p1.x - p2.x) * (p1.x - p2.x)) + ((long)(p1.y - p2.y) * (p1.y - p2.y)));
+        }
+        /*public static XYPosition[] GetSquareRange(uint edgeLen) // 从THUAI4的BULLET.CS移植而来，不知还有用否
+        {
+            XYPosition[] range = new XYPosition[edgeLen * edgeLen];
+            int offset = (int)(edgeLen >> 1);
+            for (int i = 0; i < (int)edgeLen; ++i)
+            {
+                for (int j = 0; j < (int)edgeLen; ++j)
+                {
+                    range[i * edgeLen + j].x = i - offset;
+                    range[i * edgeLen + j].y = j - offset;
+                }
+            }
+            return range;
+        }*/
+        public Vector2 ToVector2()
+        {
+            return new Vector2(this.x, this.y);
+        }
+    }
+}