diff --git a/src/net/torvald/terrarum/gameworld/GameWorld.kt b/src/net/torvald/terrarum/gameworld/GameWorld.kt
index 99486f9a3..2f869a999 100644
--- a/src/net/torvald/terrarum/gameworld/GameWorld.kt
+++ b/src/net/torvald/terrarum/gameworld/GameWorld.kt
@@ -8,7 +8,6 @@ import net.torvald.terrarum.serialise.ReadLayerDataLzma
 import org.dyn4j.geometry.Vector2
 
 typealias BlockAddress = Long
-typealias BlockDamage = Float
 
 open class GameWorld {
 
@@ -42,8 +41,10 @@ open class GameWorld {
     /** Tilewise spawn point */
     var spawnY: Int
 
-    val wallDamages: HashMap<BlockAddress, BlockDamage>
-    val terrainDamages: HashMap<BlockAddress, BlockDamage>
+    val wallDamages: HashMap<BlockAddress, Float>
+    val terrainDamages: HashMap<BlockAddress, Float>
+    val fluidTypes: HashMap<BlockAddress, Int>
+    val fluidFills: HashMap<BlockAddress, Float>
 
     //public World physWorld = new World( new Vec2(0, -Terrarum.game.gravitationalAccel) );
     //physics
@@ -74,8 +75,10 @@ open class GameWorld {
         layerTerrainLowBits = PairedMapLayer(width, height)
         layerWallLowBits = PairedMapLayer(width, height)
 
-        wallDamages = HashMap<BlockAddress, BlockDamage>()
-        terrainDamages = HashMap<BlockAddress, BlockDamage>()
+        wallDamages = HashMap<BlockAddress, Float>()
+        terrainDamages = HashMap<BlockAddress, Float>()
+        fluidTypes = HashMap<BlockAddress, Int>()
+        fluidFills = HashMap<BlockAddress, Float>()
 
         // temperature layer: 2x2 is one cell
         //layerThermal = MapLayerHalfFloat(width, height, averageTemperature)
@@ -100,6 +103,8 @@ open class GameWorld {
 
         wallDamages = layerData.wallDamages
         terrainDamages = layerData.terrainDamages
+        fluidTypes = layerData.fluidTypes
+        fluidFills = layerData.fluidFills
 
         spawnX = layerData.spawnX
         spawnY = layerData.spawnY
diff --git a/src/net/torvald/terrarum/serialise/ReadLayerDataLzma.kt b/src/net/torvald/terrarum/serialise/ReadLayerDataLzma.kt
index 343f96d05..d1cace49e 100644
--- a/src/net/torvald/terrarum/serialise/ReadLayerDataLzma.kt
+++ b/src/net/torvald/terrarum/serialise/ReadLayerDataLzma.kt
@@ -3,7 +3,6 @@ package net.torvald.terrarum.serialise
 import com.badlogic.gdx.utils.compression.Lzma
 import net.torvald.terrarum.AppLoader.printdbg
 import net.torvald.terrarum.gameworld.BlockAddress
-import net.torvald.terrarum.gameworld.BlockDamage
 import net.torvald.terrarum.gameworld.MapLayer
 import net.torvald.terrarum.gameworld.PairedMapLayer
 import net.torvald.terrarum.realestate.LandUtil
@@ -155,8 +154,10 @@ internal object ReadLayerDataLzma {
 
         val spawnPoint = LandUtil.resolveBlockAddr(width, spawnAddress)
 
-        val terrainDamages = HashMap<BlockAddress, BlockDamage>()
-        val wallDamages = HashMap<BlockAddress, BlockDamage>()
+        val terrainDamages = HashMap<BlockAddress, Float>()
+        val wallDamages = HashMap<BlockAddress, Float>()
+        val fluidTypes = HashMap<BlockAddress, Int>()
+        val fluidFills = HashMap<BlockAddress, Float>()
 
         // parse terrain damages
         for (c in 0 until payloadBytes["TdMG"]!!.size step 10) {
@@ -179,6 +180,9 @@ internal object ReadLayerDataLzma {
             wallDamages[tileAddr.toLittleInt48()] = value.toLittleFloat()
         }
 
+
+        // TODO parse fluid(Types|Fills)
+
         
         return LayerData(
                 MapLayer(width, height, payloadBytes["WALL_MSB"]!!),
@@ -189,7 +193,7 @@ internal object ReadLayerDataLzma {
 
                 spawnPoint.first, spawnPoint.second,
 
-                wallDamages, terrainDamages
+                wallDamages, terrainDamages, fluidTypes, fluidFills
         )
     }
 
@@ -209,8 +213,10 @@ internal object ReadLayerDataLzma {
 
             val spawnX: Int,
             val spawnY: Int,
-            val wallDamages: HashMap<BlockAddress, BlockDamage>,
-            val terrainDamages: HashMap<BlockAddress, BlockDamage>
+            val wallDamages: HashMap<BlockAddress, Float>,
+            val terrainDamages: HashMap<BlockAddress, Float>,
+            val fluidTypes: HashMap<BlockAddress, Int>,
+            val fluidFills: HashMap<BlockAddress, Float>
     )
 
     private fun ByteArray.shiftLeftBy(size: Int, fill: Byte = 0.toByte()) {
diff --git a/src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt b/src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt
index dafdd42ee..d1be611f4 100644
--- a/src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt
+++ b/src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt
@@ -188,13 +188,13 @@ object LightmapRenderer {
 
         /**
          * Updating order:
-         * +--------+   +--+-----+   +-----+--+   +--------+ -
+         * ,--------.   ,--+-----.   ,-----+--.   ,--------. -
          * |↘       |   |  |    3|   |3    |  |   |       ↙| ↕︎ overscan_open / overscan_opaque
          * |  +-----+   |  |  2  |   |  2  |  |   +-----+  | - depending on the noop_mask
          * |  |1    | → |  |1    | → |    1|  | → |    1|  |
          * |  |  2  |   |  +-----+   +-----+  |   |  2  |  |
          * |  |    3|   |↗       |   |       ↖|   |3    |  |
-         * +--+-----+   +--------+   +--------+   +-----+--+
+         * `--+-----'   `--------'   `--------'   `-----+--'
          * round:   1            2            3            4
          * for all lightmap[y][x]
          */
diff --git a/work_files/GameDesign/FLUID_SIMULATION.md b/work_files/GameDesign/FLUID_SIMULATION.md
new file mode 100644
index 000000000..199ea350f
--- /dev/null
+++ b/work_files/GameDesign/FLUID_SIMULATION.md
@@ -0,0 +1,12 @@
+#### Before we begin, please read following articles:
+
+- Celluar Automata https://w-shadow.com/blog/2009/09/01/simple-fluid-simulation/
+- Pressure sim in DF http://www.gamasutra.com/view/feature/131954/interview_the_making_of_dwarf_.php
+
+### Serialisation
+- FluidType: Hashed list of BlockAddress, Int
+- FluidFill: Hashed list of BlockAddress, Float32
+
+### Notes
+- By doing this, you don’t need 16 blocks to represent a water; you only need 1 block for all kinds of fluids
+- Storing the overfill (treat water as compressible) is important, will work as a temporary storage until the overfill is resolved, and rim of the update area will always be overfilled before they get updated