diff --git a/usermods/user_fx/user_fx.cpp b/usermods/user_fx/user_fx.cpp
index bcff5a0190..7914a1c4d3 100644
--- a/usermods/user_fx/user_fx.cpp
+++ b/usermods/user_fx/user_fx.cpp
@@ -2,6 +2,9 @@
 
 // for information how FX metadata strings work see https://kno.wled.ge/interfaces/json-api/#effect-metadata
 
+// paletteBlend: 0 - wrap when moving, 1 - always wrap, 2 - never wrap, 3 - none (undefined)
+#define PALETTE_SOLID_WRAP   (strip.paletteBlend == 1 || strip.paletteBlend == 3)
+
 // static effect, used if an effect fails to initialize
 static void mode_static(void) {
   SEGMENT.fill(SEGCOLOR(0));
@@ -93,6 +96,296 @@ unsigned dataSize = cols * rows;  // SEGLEN (virtual length) is equivalent to vW
 static const char _data_FX_MODE_DIFFUSIONFIRE[] PROGMEM = "Diffusion Fire@!,Spark rate,Diffusion Speed,Turbulence,,Use palette;;Color;;2;pal=35";
 
 
+/*
+/  Lava Lamp 2D effect
+*   Uses particles to simulate rising blobs of "lava" or wax
+*   Particles slowly rise, merge to create organic flowing shapes, and then fall to the bottom to start again
+*   Created by Bob Loeffler using claude.ai
+*   The first slider sets the number of active blobs
+*   The second slider sets the size range of the blobs
+*   The third slider sets the damping value for horizontal blob movement
+*   The first checkbox sets the color mode (color wheel or palette)
+*   The second checkbox sets the attraction of blobs (checked will make the blobs attract other close blobs horizontally)
+*   aux0 keeps track of the blob size value
+*   aux1 keeps track of the number of blobs
+*/
+
+typedef struct LavaParticle {
+  float    x, y;         // Position
+  float    vx, vy;       // Velocity
+  float    size;         // Blob size
+  uint8_t  hue;          // Color
+  bool     active;       // will not be displayed if false
+  uint16_t delayTop;     // number of frames to wait at top before falling again
+  bool     idleTop;      // sitting idle at the top
+  uint16_t delayBottom;  // number of frames to wait at bottom before rising again
+  bool     idleBottom;   // sitting idle at the bottom
+} LavaParticle;
+
+static void mode_2D_lavalamp(void) {
+  if (!strip.isMatrix || !SEGMENT.is2D()) FX_FALLBACK_STATIC; // not a 2D set-up
+  
+  const uint16_t cols = SEG_W;
+  const uint16_t rows = SEG_H;
+  constexpr float MAX_BLOB_RADIUS = 20.0f;  // cap to prevent frame rate drops on large matrices
+  constexpr size_t MAX_LAVA_PARTICLES = 34;  // increasing this value could cause slowness for large matrices
+  constexpr size_t MAX_TOP_FPS_DELAY = 900;  // max delay when particles are at the top
+  constexpr size_t MAX_BOTTOM_FPS_DELAY = 1200;  // max delay when particles are at the bottom
+
+  // Allocate per-segment storage
+  if (!SEGENV.allocateData(sizeof(LavaParticle) * MAX_LAVA_PARTICLES)) FX_FALLBACK_STATIC;
+  LavaParticle* lavaParticles = reinterpret_cast<LavaParticle*>(SEGENV.data);
+
+  // Initialize particles on first call
+  if (SEGENV.call == 0) {
+    for (int i = 0; i < MAX_LAVA_PARTICLES; i++) {
+      lavaParticles[i].active = false;
+    }
+  }
+
+  // Track particle size and particle count slider changes, re-initialize if either changes
+  uint8_t currentNumParticles = (SEGMENT.intensity >> 3) + 3;
+  uint8_t currentSize = SEGMENT.custom1;
+  if (currentNumParticles > MAX_LAVA_PARTICLES) currentNumParticles = MAX_LAVA_PARTICLES;
+  bool needsReinit = (currentSize != SEGENV.aux0) || (currentNumParticles != SEGENV.aux1);
+
+  if (needsReinit) {
+    for (int i = 0; i < MAX_LAVA_PARTICLES; i++) {
+      lavaParticles[i].active = false;
+    }
+    SEGENV.aux0 = currentSize;
+    SEGENV.aux1 = currentNumParticles;
+  }
+
+  uint8_t size = currentSize;
+  uint8_t numParticles = currentNumParticles;
+  
+  // blob size based on matrix width
+  const float minSize = cols * 0.15f; // Minimum 15% of width
+  const float maxSize = cols * 0.4f;  // Maximum 40% of width
+  float sizeRange = (maxSize - minSize) * (size / 255.0f);
+  int rangeInt = max(1, (int)(sizeRange));
+
+  // calculate the spawning area for the particles
+  const float spawnXStart = cols * 0.20f;
+  const float spawnXWidth = cols * 0.60f;
+  int spawnX = max(1, (int)(spawnXWidth));
+
+  // Spawn new particles at the bottom near the center
+  for (int i = 0; i < MAX_LAVA_PARTICLES; i++) {
+    if (!lavaParticles[i].active && hw_random8() < 32) { // spawn when slot available
+      // Spawn in the middle 60% of the matrix width
+      lavaParticles[i].x = spawnXStart + (float)hw_random16(spawnX);
+      lavaParticles[i].y = rows - 1;
+      lavaParticles[i].vx = (hw_random16(7) - 3) / 250.0f;
+      lavaParticles[i].vy = -(hw_random16(20) + 10) / 100.0f * 0.3f;
+      
+      lavaParticles[i].size = minSize + (float)hw_random16(rangeInt);
+      if (lavaParticles[i].size > MAX_BLOB_RADIUS) lavaParticles[i].size = MAX_BLOB_RADIUS;
+
+      lavaParticles[i].hue = hw_random8();
+      lavaParticles[i].active = true;
+
+      // Set random delays when particles are at top and bottom
+      lavaParticles[i].delayTop = hw_random16(MAX_TOP_FPS_DELAY);
+      lavaParticles[i].delayBottom = hw_random16(MAX_BOTTOM_FPS_DELAY);
+      lavaParticles[i].idleBottom = true;
+      break;
+    }
+  }
+
+  // Fade background slightly for trailing effect
+  SEGMENT.fadeToBlackBy(40);
+  
+  // Update and draw particles
+  int activeCount = 0;
+  unsigned long currentMillis = strip.now;
+  for (int i = 0; i < MAX_LAVA_PARTICLES; i++) {
+    if (!lavaParticles[i].active) continue;
+    activeCount++;
+
+    // Keep particle count on target by deactivating excess particles
+    if (activeCount > numParticles) {
+      lavaParticles[i].active = false;
+      activeCount--;
+      continue;
+    }
+
+    LavaParticle *p = &lavaParticles[i];
+    
+    // Physics update
+    p->x += p->vx;
+    p->y += p->vy;
+    
+    // Optional particle/blob attraction
+    if (SEGMENT.check2) {
+      for (int j = 0; j < MAX_LAVA_PARTICLES; j++) {
+        if (i == j || !lavaParticles[j].active) continue;
+        
+        LavaParticle *other = &lavaParticles[j];
+        
+        // Skip attraction if moving in same vertical direction (both up or both down)
+        if ((p->vy < 0 && other->vy < 0) || (p->vy > 0 && other->vy > 0)) continue;
+        
+        float dx = other->x - p->x;
+        float dy = other->y - p->y;
+
+        // Apply weak horizontal attraction only
+        float attractRange = p->size + other->size;
+        float distSq = dx*dx + dy*dy;
+        float attractRangeSq = attractRange * attractRange;
+        if (distSq > 0 && distSq < attractRangeSq) {
+          float dist = sqrt(distSq); // Only compute sqrt when needed
+          float force = (1.0f - (dist / attractRange)) * 0.0001f;
+          p->vx += (dx / dist) * force;
+        }
+      }
+    }
+
+    // Horizontal oscillation (makes it more organic)
+    float damping= map(SEGMENT.custom2, 0, 255, 87, 97) / 100.0f;
+    p->vx += sin((currentMillis / 1000.0f + i) * 0.5f) * 0.002f; // Reduced oscillation
+    //p->vx *= 0.92f; // Stronger damping for less drift
+    p->vx *= damping; // damping for more or less horizontal drift
+
+    // Bounce off sides (don't affect vertical velocity)
+    if (p->x < 0) {
+      p->x = 0;
+      p->vx = abs(p->vx); // reverse horizontal
+    }
+    if (p->x >= cols) {
+      p->x = cols - 1;
+      p->vx = -abs(p->vx); // reverse horizontal
+    }
+
+    // Adjust rise/fall velocity depending on approx distance from heat source (at bottom)
+    // In top 1/4th of rows...
+    if (p->y < rows * .25f) {
+      if (p->vy >= 0) {  // if going down, delay the particles so they won't go down immediately
+        if (p->delayTop > 0 && p->idleTop) {
+          p->vy = 0.0f;
+          p->delayTop--;
+          p->idleTop = true;
+        } else {
+          p->vy = 0.01f;
+          p->delayTop = hw_random16(MAX_TOP_FPS_DELAY);
+          p->idleTop = false;
+        }
+      } else if (p->vy <= 0) {  // if going up, slow down the rise rate
+        p->vy = -0.03f;
+      }
+    }
+
+    // In next 1/4th of rows...
+    if (p->y <= rows * .50f && p->y >= rows * .25f) {
+      if (p->vy > 0) {  // if going down, speed up the fall rate
+        p->vy = 0.03f;
+      } else if (p->vy <= 0) {  // if going up, speed up the rise rate a little more
+        p->vy = -0.05f;
+      }
+    }
+
+    // In next 1/4th of rows...
+    if (p->y <= rows * .75f && p->y >= rows * .50f) {
+      if (p->vy > 0) {  // if going down, speed up the fall rate a little more
+        p->vy = 0.04f;
+      } else if (p->vy <= 0) {  // if going up, speed up the rise rate
+        p->vy = -0.03f;
+      }
+    }
+
+    // In bottom 1/4th of rows...
+    if (p->y > rows * .75f) {
+      if (p->vy >= 0) {  // if going down, slow down the fall rate
+        p->vy = 0.02f;
+      } else if (p->vy <= 0) {  // if going up, delay the particles so they won't go up immediately
+        if (p->delayBottom > 0 && p->idleBottom) {
+          p->vy = 0.0f;
+          p->delayBottom--;
+          p->idleBottom = true;
+        } else {
+          p->vy = -0.01f;
+          p->delayBottom = hw_random16(MAX_BOTTOM_FPS_DELAY);
+          p->idleBottom = false;
+        }
+      }
+    }
+
+    // Boundary handling with reversal of direction
+    // When reaching TOP (y=0 area), reverse to fall back down, but need to delay first
+    if (p->y <= 0.5f * p->size) {
+      p->y = 0.5f * p->size;
+      if (p->vy < 0) {
+        p->vy = 0.005f;  // set to a tiny positive value to start falling very slowly
+        p->idleTop = true;
+      }
+    }
+
+    // When reaching BOTTOM (y=rows-1 area), reverse to rise back up, but need to delay first
+    if (p->y >= rows - 0.5f * p->size) {
+      p->y = rows - 0.5f * p->size;
+      if (p->vy > 0) {
+        p->vy = -0.005f;  // set to a tiny negative value to start rising very slowly
+        p->idleBottom = true;
+      }
+    }
+
+    // Get color
+    uint32_t color;
+    if (SEGMENT.check1) {
+      color = SEGMENT.color_wheel(p->hue);  // Random colors mode
+    } else {
+      color = SEGMENT.color_from_palette(p->hue, true, PALETTE_SOLID_WRAP, 0);   // Palette mode
+    }
+    
+    // Extract RGB and apply life/opacity
+    uint8_t w = (W(color) * 255) >> 8;
+    uint8_t r = (R(color) * 255) >> 8;
+    uint8_t g = (G(color) * 255) >> 8;
+    uint8_t b = (B(color) * 255) >> 8;
+
+    // Draw blob with sub-pixel accuracy using bilinear distribution
+    float sizeSq = p->size * p->size;
+
+    // Get fractional offsets of particle center
+    float fracX = p->x - floorf(p->x);
+    float fracY = p->y - floorf(p->y);
+    int centerX = (int)floorf(p->x);
+    int centerY = (int)floorf(p->y);
+
+    for (int dy = -(int)p->size - 1; dy <= (int)p->size + 1; dy++) {
+      for (int dx = -(int)p->size - 1; dx <= (int)p->size + 1; dx++) {
+        int px = centerX + dx;
+        int py = centerY + dy;
+        
+        if (px < 0 || px >= cols || py < 0 || py >= rows) continue;
+
+        // Sub-pixel distance: measure from true float center to pixel center
+        float subDx = dx - fracX;  // distance from true center to this pixel's center
+        float subDy = dy - fracY;
+        float distSq = subDx * subDx + subDy * subDy;
+
+        if (distSq < sizeSq) {
+          float intensity = 1.0f - (distSq / sizeSq);
+          intensity = intensity * intensity; // smooth falloff
+
+          uint8_t bw = (uint8_t)(w * intensity);
+          uint8_t br = (uint8_t)(r * intensity);
+          uint8_t bg = (uint8_t)(g * intensity);
+          uint8_t bb = (uint8_t)(b * intensity);
+
+          uint32_t existing = SEGMENT.getPixelColorXY(px, py);
+          uint32_t newColor = RGBW32(br, bg, bb, bw);
+          SEGMENT.setPixelColorXY(px, py, color_add(existing, newColor));
+        }
+      }
+    }
+  }
+}
+static const char _data_FX_MODE_2D_LAVALAMP[] PROGMEM = "Lava Lamp@,# of blobs,Blob size,H. Damping,,Color mode,Attract;;!;2;ix=64,c2=192,o2=1,pal=47";
+
+
+
 /////////////////////
 //  UserMod Class  //
 /////////////////////
@@ -102,6 +395,7 @@ class UserFxUsermod : public Usermod {
  public:
   void setup() override {
     strip.addEffect(255, &mode_diffusionfire, _data_FX_MODE_DIFFUSIONFIRE);
+    strip.addEffect(255, &mode_2D_lavalamp, _data_FX_MODE_2D_LAVALAMP);
 
     ////////////////////////////////////////
     //  add your effect function(s) here  //