diff --git a/client/shaders/fog.gdshader b/client/shaders/fog.gdshader
index 6287eb0ae..99dcb17a4 100644
--- a/client/shaders/fog.gdshader
+++ b/client/shaders/fog.gdshader
@@ -1,10 +1,9 @@
 shader_type canvas_item;
 
-// D-059: 3-state fog shader (simplified from 5-layer by #569).
+// D-059/D-015: 3-state fog shader (simplified from 5-layer by #569).
 // State 1: Clear (forward cone) — transparent, soft Gaussian gradient edge (3-4 tile radius)
-// State 2: Explored (out of cone, EXP_EXPLORED) — two sub-zones by vis proximity:
-//   a) Light fog (near cone gradient): alpha 0.25-0.35, neutral dark, 8-10s breathe
-//   b) Deep fog (far from cone, vis≈0): alpha 0.55-0.70, zone temperature tint, 15-20s breathe
+// State 2: Explored (out of cone) — light fog overlay, alpha 0.25-0.35, zone temperature tint,
+//          8-10s Perlin breathe. Art and information preserved, just "not fresh" (D-015).
 // State 3: Unexplored — solid near-black #12141a
 // D-033: Entity colors are NOT affected — they render above the fog overlay (z-layer 5).
 // D-046: Zone temperature tint from zone_tint_tex — warm=bar, cool=hub, neutral=corridor.
@@ -23,7 +22,6 @@ uniform float time;          // Seconds since start
 uniform bool debug_exploration = false; // When true, render raw exploration texture
 
 const vec3 UNEXPLORED_COLOR = vec3(0.071, 0.078, 0.102);  // #12141a
-const vec3 DARK_OVERLAY = vec3(0.02, 0.02, 0.05);         // neutral dark (light fog zone)
 
 // Soft gradient via 7x7 Gaussian blur on visibility (sigma 2.0).
 // Spreads the cone boundary into a 3-4 tile radius gradient — no hard tile-stepped edges.
@@ -42,6 +40,23 @@ float sample_visibility(vec2 uv) {
     return sum / weight;
 }
 
+// Soft gradient on exploration boundary (5x5, sigma 1.5).
+// Prevents hard tile-stepped staircase at explored/unexplored edge.
+float sample_exploration(vec2 uv) {
+    vec2 t = 1.0 / map_size;
+    float sum = 0.0;
+    float weight = 0.0;
+    for (float dy = -2.0; dy <= 2.0; dy += 1.0) {
+        for (float dx = -2.0; dx <= 2.0; dx += 1.0) {
+            float w = exp(-(dx * dx + dy * dy) / 4.5);
+            vec2 sample_uv = clamp(uv + vec2(dx, dy) * t, vec2(0.0), vec2(1.0));
+            sum += texture(exploration_tex, sample_uv).r * w;
+            weight += w;
+        }
+    }
+    return sum / weight;
+}
+
 void fragment() {
     vec2 world_px = rect_pos + UV * rect_sz;
     vec2 tile = world_px / tile_size;
@@ -69,10 +84,11 @@ void fragment() {
 
     float vis_raw = texture(visibility_tex, tex_uv).r;
     float vis = sample_visibility(tex_uv);
-    float explored = texture(exploration_tex, tex_uv).r;
+    float explored_raw = texture(exploration_tex, tex_uv).r;
+    float explored = sample_exploration(tex_uv);
 
-    // Prevent gradient bleed into never-explored tiles
-    if (explored < 0.01 && vis_raw < 0.01) {
+    // Prevent gradient bleed into never-explored tiles (use raw, unblurred value)
+    if (explored_raw < 0.01 && vis_raw < 0.01) {
         vis = 0.0;
     }
 
@@ -80,39 +96,19 @@ void fragment() {
         // Unexplored: solid near-black — information zero
         COLOR = vec4(UNEXPLORED_COLOR, 1.0);
     } else {
-        // Light fog noise — fast cycle (~9s), ±0.05 breathing
-        float noise_fast = texture(noise_tex, tile * 0.03 + vec2(time * 0.11, time * 0.07)).r;
-        // Deep fog noise — slow cycle (~20s), ±0.075 breathing (more pronounced)
-        float noise_slow = texture(noise_tex, tile * 0.02 + vec2(time * 0.05, time * 0.035)).r;
+        // Fog noise — 8-10s breathe cycle, ±0.05 symmetric around baseline
+        float noise_val = texture(noise_tex, tile * 0.03 + vec2(time * 0.11, time * 0.07)).r;
+        float fog_alpha = 0.30 + (noise_val * 2.0 - 1.0) * 0.05;  // 0.25-0.35
 
-        // Light fog: alpha 0.25-0.35 (centered at 0.30, ±0.05 breathe)
-        // Noise remapped to [-1,+1] for symmetric breathing around baseline.
-        float light_fog_alpha = 0.30 + (noise_fast * 2.0 - 1.0) * 0.05;
-
-        // Deep fog: alpha 0.55-0.70 (centered at 0.625, ±0.075 breathe)
-        float deep_fog_alpha = 0.625 + (noise_slow * 2.0 - 1.0) * 0.075;
-
-        // Blend deep <-> light fog by proximity to cone:
-        //   vis=0   (far from cone)  → deep_factor=1 → deep fog
-        //   vis=0.3 (cone gradient)  → deep_factor=0 → light fog
-        //   vis=0.85+ (inside cone)  → clarity=1     → transparent (clear)
-        float deep_factor = 1.0 - smoothstep(0.0, 0.30, vis);
-        float fog_alpha = mix(light_fog_alpha, deep_fog_alpha, deep_factor);
-
-        // Zone temperature tint (D-059/D-046/D-077):
-        // Deep fog color uses zone_tint_tex; light fog uses neutral DARK_OVERLAY.
-        // zone_tint_tex is populated per-tile from server zone_id via fog_state.gd.
+        // Zone temperature tint (D-046/D-077): subtle warm/cool/neutral per zone
         vec3 zone_tint = texture(zone_tint_tex, tex_uv).rgb;
 
-        // Clarity ramp: transparent inside cone, fogged at edges and beyond
+        // Clarity ramp: transparent inside cone, light fog at edges and beyond
         float clarity = smoothstep(0.0, 0.85, vis);
         float alpha = mix(fog_alpha, 0.0, clarity);
+        vec3 color = mix(zone_tint, vec3(0.0), clarity);
 
-        // Color: deep fog → zone temperature tint; light fog → neutral dark overlay
-        vec3 fog_color = mix(DARK_OVERLAY, zone_tint, deep_factor);
-        vec3 color = mix(fog_color, vec3(0.0), clarity);
-
-        // Soft edge between explored and unexplored
+        // Soft edge between explored and unexplored (blurred to avoid staircase)
         float exp_fade = smoothstep(0.0, 0.3, explored);
         alpha = mix(1.0, alpha, exp_fade);
         color = mix(UNEXPLORED_COLOR, color, exp_fade);