diff --git a/server/src/Hokm.Server/Profiles/Gamification.cs b/server/src/Hokm.Server/Profiles/Gamification.cs
index 20a105e..323e9d3 100644
--- a/server/src/Hokm.Server/Profiles/Gamification.cs
+++ b/server/src/Hokm.Server/Profiles/Gamification.cs
@@ -56,12 +56,13 @@ public static class Gamification
     // metric: wins|kotsFor|bestWinStreak|shutoutWins|games|tricks|level ; ratingFloor>0 = rank ach.
     private record AchDef(string Id, string? Metric, int RatingFloor, int Goal, int Coin, string NameFa, string NameEn, string Icon);
     // Mirrors src/lib/online/gamification.ts (same ids/goals/coins/metrics).
-    private static int Coin(int g) => Math.Min(1500, Math.Max(50, (int)Math.Floor((40.0 + g * 6) / 50.0 + 0.5) * 50));
+    // Reward escalates strictly per milestone tier (50, 150, 250 … capped 1500).
+    private static int CoinAt(int i) => Math.Min(1500, 50 + i * 100);
     private static string Fa(int n) =>
         new string(n.ToString().Select(c => c is >= '0' and <= '9' ? "۰۱۲۳۴۵۶۷۸۹"[c - '0'] : c).ToArray());
 
     private static AchDef[] Tier(string metric, string prefix, string icon, int[] goals, Func<int, string> faName, Func<int, string> enName)
-        => goals.Select(g => new AchDef($"{prefix}_{g}", metric, 0, g, Coin(g), faName(g), enName(g), icon)).ToArray();
+        => goals.Select((g, i) => new AchDef($"{prefix}_{g}", metric, 0, g, CoinAt(i), faName(g), enName(g), icon)).ToArray();
 
     private static readonly AchDef[] Achs = BuildAchs();
     private static AchDef[] BuildAchs()
diff --git a/src/lib/online/gamification.ts b/src/lib/online/gamification.ts
index fb237c4..539c411 100644
--- a/src/lib/online/gamification.ts
+++ b/src/lib/online/gamification.ts
@@ -253,12 +253,13 @@ function tier(
   faDesc: (g: string) => string,
   enDesc: (g: number) => string
 ): AchievementDef[] {
-  return goals.map((g) => ({
+  return goals.map((g, i) => ({
     id: `${prefix}_${g}`,
     category,
     metric,
     goal: g,
-    coinReward: Math.min(1500, Math.max(50, Math.round((40 + g * 6) / 50) * 50)),
+    // Reward escalates strictly per milestone tier (50, 150, 250 … capped 1500).
+    coinReward: Math.min(1500, 50 + i * 100),
     icon,
     nameFa: faName(faNum(g)),
     nameEn: enName(g),