diff --git a/README.md b/README.md
index 86da5d7..a50b2c0 100644
--- a/README.md
+++ b/README.md
@@ -24,7 +24,7 @@ If you would like to propose a challenge, this project is open source, so feel f
 
 ## Challenges
 
-Check [all 50 challenges](https://angular-challenges.vercel.app/)
+Check [all 51 challenges](https://angular-challenges.vercel.app/)
 
 ## Contributors ✨
 
diff --git a/apps/signal/51-function-call-effect/.eslintrc.json b/apps/signal/51-function-call-effect/.eslintrc.json
new file mode 100644
index 0000000..8ebcbfd
--- /dev/null
+++ b/apps/signal/51-function-call-effect/.eslintrc.json
@@ -0,0 +1,36 @@
+{
+  "extends": ["../../../.eslintrc.json"],
+  "ignorePatterns": ["!**/*"],
+  "overrides": [
+    {
+      "files": ["*.ts"],
+      "extends": [
+        "plugin:@nx/angular",
+        "plugin:@angular-eslint/template/process-inline-templates"
+      ],
+      "rules": {
+        "@angular-eslint/directive-selector": [
+          "error",
+          {
+            "type": "attribute",
+            "prefix": "app",
+            "style": "camelCase"
+          }
+        ],
+        "@angular-eslint/component-selector": [
+          "error",
+          {
+            "type": "element",
+            "prefix": "app",
+            "style": "kebab-case"
+          }
+        ]
+      }
+    },
+    {
+      "files": ["*.html"],
+      "extends": ["plugin:@nx/angular-template"],
+      "rules": {}
+    }
+  ]
+}
diff --git a/apps/signal/51-function-call-effect/README.md b/apps/signal/51-function-call-effect/README.md
new file mode 100644
index 0000000..6d45433
--- /dev/null
+++ b/apps/signal/51-function-call-effect/README.md
@@ -0,0 +1,13 @@
+# Function call in effect
+
+> author: thomas-laforge
+
+### Run Application
+
+```bash
+npx nx serve signal-function-call-effect
+```
+
+### Documentation and Instruction
+
+Challenge documentation is [here](https://angular-challenges.vercel.app/challenges/angular/51-function-call-effect/).
diff --git a/apps/signal/51-function-call-effect/project.json b/apps/signal/51-function-call-effect/project.json
new file mode 100644
index 0000000..e84c793
--- /dev/null
+++ b/apps/signal/51-function-call-effect/project.json
@@ -0,0 +1,72 @@
+{
+  "name": "signal-function-call-effect",
+  "$schema": "../../../node_modules/nx/schemas/project-schema.json",
+  "projectType": "application",
+  "prefix": "app",
+  "sourceRoot": "apps/signal/51-function-call-effect/src",
+  "tags": [],
+  "targets": {
+    "build": {
+      "executor": "@angular-devkit/build-angular:application",
+      "outputs": ["{options.outputPath}"],
+      "options": {
+        "outputPath": "dist/apps/signal/51-function-call-effect",
+        "index": "apps/signal/51-function-call-effect/src/index.html",
+        "browser": "apps/signal/51-function-call-effect/src/main.ts",
+        "polyfills": ["zone.js"],
+        "tsConfig": "apps/signal/51-function-call-effect/tsconfig.app.json",
+        "inlineStyleLanguage": "scss",
+        "assets": [
+          "apps/signal/51-function-call-effect/src/favicon.ico",
+          "apps/signal/51-function-call-effect/src/assets"
+        ],
+        "styles": ["apps/signal/51-function-call-effect/src/styles.scss"],
+        "scripts": []
+      },
+      "configurations": {
+        "production": {
+          "budgets": [
+            {
+              "type": "initial",
+              "maximumWarning": "500kb",
+              "maximumError": "1mb"
+            },
+            {
+              "type": "anyComponentStyle",
+              "maximumWarning": "2kb",
+              "maximumError": "4kb"
+            }
+          ],
+          "outputHashing": "all"
+        },
+        "development": {
+          "optimization": false,
+          "extractLicenses": false,
+          "sourceMap": true
+        }
+      },
+      "defaultConfiguration": "production"
+    },
+    "serve": {
+      "executor": "@angular-devkit/build-angular:dev-server",
+      "configurations": {
+        "production": {
+          "buildTarget": "signal-function-call-effect:build:production"
+        },
+        "development": {
+          "buildTarget": "signal-function-call-effect:build:development"
+        }
+      },
+      "defaultConfiguration": "development"
+    },
+    "extract-i18n": {
+      "executor": "@angular-devkit/build-angular:extract-i18n",
+      "options": {
+        "buildTarget": "signal-function-call-effect:build"
+      }
+    },
+    "lint": {
+      "executor": "@nx/eslint:lint"
+    }
+  }
+}
diff --git a/apps/signal/51-function-call-effect/src/app/action.component.ts b/apps/signal/51-function-call-effect/src/app/action.component.ts
new file mode 100644
index 0000000..bbdc824
--- /dev/null
+++ b/apps/signal/51-function-call-effect/src/app/action.component.ts
@@ -0,0 +1,45 @@
+import {
+  ChangeDetectionStrategy,
+  Component,
+  effect,
+  inject,
+  signal,
+} from '@angular/core';
+import { FormsModule } from '@angular/forms';
+import { UserService } from './user.service';
+
+@Component({
+  standalone: true,
+  imports: [FormsModule],
+  selector: 'app-actions',
+  template: `
+    <form class="mx-auto max-w-sm">
+      <label for="actions" class="mb-2 block text-sm font-medium text-gray-900">
+        Choose an action
+      </label>
+      <select
+        name="actions"
+        [(ngModel)]="action"
+        id="actions"
+        class="block w-full rounded-lg border border-gray-300 bg-gray-50 p-2.5 text-sm text-gray-900 focus:border-blue-500 focus:ring-blue-500">
+        <option selected>Please select an action</option>
+        @for (action of actions; track $index) {
+          <option value="{{ action }}">{{ action }}</option>
+        }
+      </select>
+    </form>
+  `,
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class ActionsComponent {
+  private userService = inject(UserService);
+  protected action = signal(undefined);
+
+  protected actions = ['Create', 'Read', 'Update', 'Delete'];
+
+  constructor() {
+    effect(() => {
+      this.userService.log(this.action() ?? 'No action selected');
+    });
+  }
+}
diff --git a/apps/signal/51-function-call-effect/src/app/app.component.ts b/apps/signal/51-function-call-effect/src/app/app.component.ts
new file mode 100644
index 0000000..69fd23f
--- /dev/null
+++ b/apps/signal/51-function-call-effect/src/app/app.component.ts
@@ -0,0 +1,34 @@
+import { ChangeDetectionStrategy, Component, inject } from '@angular/core';
+import { FormsModule } from '@angular/forms';
+import { ActionsComponent } from './action.component';
+import { UserService } from './user.service';
+
+@Component({
+  standalone: true,
+  imports: [FormsModule, ActionsComponent],
+  selector: 'app-root',
+  template: `
+    <nav class="flex w-full items-center border border-b">
+      Profile selected:
+      <form class="m-4 w-48">
+        <select
+          [(ngModel)]="userService.name"
+          name="name"
+          class="block w-full rounded-lg border border-gray-300 bg-gray-50 p-2.5 text-sm text-gray-900 focus:border-blue-500 focus:ring-blue-500 ">
+          <option selected>Please choose an user</option>
+          @for (user of users; track $index) {
+            <option value="{{ user }}">{{ user }}</option>
+          }
+        </select>
+      </form>
+    </nav>
+
+    <app-actions />
+  `,
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class AppComponent {
+  protected userService = inject(UserService);
+
+  protected users = ['Thomas', 'John', 'Alice', 'Bob', 'Charlie', 'David'];
+}
diff --git a/apps/signal/51-function-call-effect/src/app/app.config.ts b/apps/signal/51-function-call-effect/src/app/app.config.ts
new file mode 100644
index 0000000..81a6edd
--- /dev/null
+++ b/apps/signal/51-function-call-effect/src/app/app.config.ts
@@ -0,0 +1,5 @@
+import { ApplicationConfig } from '@angular/core';
+
+export const appConfig: ApplicationConfig = {
+  providers: [],
+};
diff --git a/apps/signal/51-function-call-effect/src/app/user.service.ts b/apps/signal/51-function-call-effect/src/app/user.service.ts
new file mode 100644
index 0000000..b43756b
--- /dev/null
+++ b/apps/signal/51-function-call-effect/src/app/user.service.ts
@@ -0,0 +1,10 @@
+import { Injectable, signal } from '@angular/core';
+
+@Injectable({ providedIn: 'root' })
+export class UserService {
+  name = signal('Thomas');
+
+  log(message: string) {
+    console.log(`${this.name()}: ${message}`);
+  }
+}
diff --git a/apps/signal/51-function-call-effect/src/assets/.gitkeep b/apps/signal/51-function-call-effect/src/assets/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/apps/signal/51-function-call-effect/src/favicon.ico b/apps/signal/51-function-call-effect/src/favicon.ico
new file mode 100644
index 0000000..317ebcb
Binary files /dev/null and b/apps/signal/51-function-call-effect/src/favicon.ico differ
diff --git a/apps/signal/51-function-call-effect/src/index.html b/apps/signal/51-function-call-effect/src/index.html
new file mode 100644
index 0000000..523bcae
--- /dev/null
+++ b/apps/signal/51-function-call-effect/src/index.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <title>angular-function-call-effect</title>
+    <base href="/" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <link rel="icon" type="image/x-icon" href="favicon.ico" />
+  </head>
+  <body>
+    <app-root></app-root>
+  </body>
+</html>
diff --git a/apps/signal/51-function-call-effect/src/main.ts b/apps/signal/51-function-call-effect/src/main.ts
new file mode 100644
index 0000000..f3a7223
--- /dev/null
+++ b/apps/signal/51-function-call-effect/src/main.ts
@@ -0,0 +1,7 @@
+import { bootstrapApplication } from '@angular/platform-browser';
+import { AppComponent } from './app/app.component';
+import { appConfig } from './app/app.config';
+
+bootstrapApplication(AppComponent, appConfig).catch((err) =>
+  console.error(err),
+);
diff --git a/apps/signal/51-function-call-effect/src/styles.scss b/apps/signal/51-function-call-effect/src/styles.scss
new file mode 100644
index 0000000..77e408a
--- /dev/null
+++ b/apps/signal/51-function-call-effect/src/styles.scss
@@ -0,0 +1,5 @@
+@tailwind base;
+@tailwind components;
+@tailwind utilities;
+
+/* You can add global styles to this file, and also import other style files */
diff --git a/apps/signal/51-function-call-effect/tailwind.config.js b/apps/signal/51-function-call-effect/tailwind.config.js
new file mode 100644
index 0000000..38183db
--- /dev/null
+++ b/apps/signal/51-function-call-effect/tailwind.config.js
@@ -0,0 +1,14 @@
+const { createGlobPatternsForDependencies } = require('@nx/angular/tailwind');
+const { join } = require('path');
+
+/** @type {import('tailwindcss').Config} */
+module.exports = {
+  content: [
+    join(__dirname, 'src/**/!(*.stories|*.spec).{ts,html}'),
+    ...createGlobPatternsForDependencies(__dirname),
+  ],
+  theme: {
+    extend: {},
+  },
+  plugins: [],
+};
diff --git a/apps/signal/51-function-call-effect/tsconfig.app.json b/apps/signal/51-function-call-effect/tsconfig.app.json
new file mode 100644
index 0000000..5822042
--- /dev/null
+++ b/apps/signal/51-function-call-effect/tsconfig.app.json
@@ -0,0 +1,10 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "../../../dist/out-tsc",
+    "types": []
+  },
+  "files": ["src/main.ts"],
+  "include": ["src/**/*.d.ts"],
+  "exclude": ["jest.config.ts", "src/**/*.test.ts", "src/**/*.spec.ts"]
+}
diff --git a/apps/signal/51-function-call-effect/tsconfig.editor.json b/apps/signal/51-function-call-effect/tsconfig.editor.json
new file mode 100644
index 0000000..a8ac182
--- /dev/null
+++ b/apps/signal/51-function-call-effect/tsconfig.editor.json
@@ -0,0 +1,6 @@
+{
+  "extends": "./tsconfig.json",
+  "include": ["src/**/*.ts"],
+  "compilerOptions": {},
+  "exclude": ["jest.config.ts", "src/**/*.test.ts", "src/**/*.spec.ts"]
+}
diff --git a/apps/signal/51-function-call-effect/tsconfig.json b/apps/signal/51-function-call-effect/tsconfig.json
new file mode 100644
index 0000000..3df17b9
--- /dev/null
+++ b/apps/signal/51-function-call-effect/tsconfig.json
@@ -0,0 +1,30 @@
+{
+  "compilerOptions": {
+    "target": "es2022",
+    "useDefineForClassFields": false,
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "strict": true,
+    "noImplicitOverride": true,
+    "noPropertyAccessFromIndexSignature": true,
+    "noImplicitReturns": true,
+    "noFallthroughCasesInSwitch": true
+  },
+  "files": [],
+  "include": [],
+  "references": [
+    {
+      "path": "./tsconfig.editor.json"
+    },
+    {
+      "path": "./tsconfig.app.json"
+    }
+  ],
+  "extends": "../../../tsconfig.base.json",
+  "angularCompilerOptions": {
+    "enableI18nLegacyMessageIdFormat": false,
+    "strictInjectionParameters": true,
+    "strictInputAccessModifiers": true,
+    "strictTemplates": true
+  }
+}
diff --git a/challenge-number.json b/challenge-number.json
index b4b38aa..7891d9a 100644
--- a/challenge-number.json
+++ b/challenge-number.json
@@ -1,6 +1,6 @@
 {
-  "total": 50,
-  "🟢": 19,
+  "total": 51,
+  "🟢": 20,
   "🟠": 121,
   "🔴": 209
 }
diff --git a/docs/src/content/docs/challenges/angular/50-bug-effect-signal.md b/docs/src/content/docs/challenges/angular/50-bug-effect-signal.md
new file mode 100644
index 0000000..0e73301
--- /dev/null
+++ b/docs/src/content/docs/challenges/angular/50-bug-effect-signal.md
@@ -0,0 +1,21 @@
+---
+title: 🟢 Bug in Effect ?
+description: Challenge 50 is about understanding why an effect is not triggered.
+author: thomas-laforge
+contributors:
+  - tomalaforge
+challengeNumber: 50
+command: angular-bug-effect-signal
+sidebar:
+  order: 19
+---
+
+## Information
+
+In this basic exercise, we aim to display an alert whenever at least one checkbox is checked.
+
+## Statement
+
+The alert correctly triggers when clicking on each checkbox separately. However, if you first click on one checkbox and then click on a second one, the alert fails to appear. Why does this happen?
+
+The objective of this challenge is to understand and correct the issue preventing the alert from appearing when the second checkbox is clicked.
diff --git a/docs/src/content/docs/challenges/signal/50-bug-effect-signal.md b/docs/src/content/docs/challenges/signal/50-bug-effect-signal.md
index f5fb178..3715b2c 100644
--- a/docs/src/content/docs/challenges/signal/50-bug-effect-signal.md
+++ b/docs/src/content/docs/challenges/signal/50-bug-effect-signal.md
@@ -9,7 +9,6 @@ challengeNumber: 50
 command: signal-bug-in-effect
 sidebar:
   order: 19
-  badge: New
 ---
 
 ## Information
diff --git a/docs/src/content/docs/challenges/signal/51-function-call-effect.md b/docs/src/content/docs/challenges/signal/51-function-call-effect.md
new file mode 100644
index 0000000..91d02bd
--- /dev/null
+++ b/docs/src/content/docs/challenges/signal/51-function-call-effect.md
@@ -0,0 +1,22 @@
+---
+title: 🟢 Function call in effect
+description: Challenge 51 is about understanding why an effect is triggered too often.
+author: thomas-laforge
+contributors:
+  - tomalaforge
+challengeNumber: 51
+command: signal-function-call-effect
+sidebar:
+  order: 20
+  badge: New
+---
+
+## Information
+
+In this second challenge focusing on Signal effects, we've introduced an input select that allows users to choose an action. Whenever an action is selected, it is logged in the console. The application also permits changes to the selected user.
+
+## Problem Statement
+
+Ideally, the system should log an action only when one is specifically selected. However, we currently face an issue where changing the user also triggers a log entry, even though we do not explicitly monitor user changes.
+
+The objective of this challenge is to identify and resolve the cause of these extra triggers. We aim to ensure that logging only occurs when an action is selected.
diff --git a/docs/src/content/docs/es/index.mdx b/docs/src/content/docs/es/index.mdx
index 2772914..cefa56b 100644
--- a/docs/src/content/docs/es/index.mdx
+++ b/docs/src/content/docs/es/index.mdx
@@ -13,7 +13,7 @@ hero:
       icon: right-arrow
       variant: primary
     - text: Ir al Desafío más reciente
-      link: /es/signal/angular/50-bug-effect-signal/
+      link: /es/challenges/signal/51-function-call-effect
       icon: rocket
     - text: Dar una estrella
       link: https://github.com/tomalaforge/angular-challenges
@@ -26,8 +26,8 @@ import MyIcon from '../../../components/MyIcon.astro';
 import SubscriptionForm from '../../../components/SubscriptionForm.astro';
 
 <CardGrid>
-<Card title="50 Desafíos">
-  Este repositorio contiene 50 Desafíos relacionados con <b>Angular</b>, <b>Nx</b>, <b>RxJS</b>, <b>Ngrx</b> y <b>Typescript</b>.
+<Card title="51 Desafíos">
+  Este repositorio contiene 51 Desafíos relacionados con <b>Angular</b>, <b>Nx</b>, <b>RxJS</b>, <b>Ngrx</b> y <b>Typescript</b>.
   Estos desafíos se resuelven en torno a problemas de la vida real o características específicas para mejorar tus habilidades.
 </Card>
 
diff --git a/docs/src/content/docs/fr/index.mdx b/docs/src/content/docs/fr/index.mdx
index 98b1b8e..e510057 100644
--- a/docs/src/content/docs/fr/index.mdx
+++ b/docs/src/content/docs/fr/index.mdx
@@ -13,7 +13,7 @@ hero:
       icon: right-arrow
       variant: primary
     - text: Aller au dernier Challenge
-      link: /fr/challenges/signal/50-bug-effect-signal/
+      link: /fr/challenges/signal/51-function-call-effect
       icon: rocket
     - text: Donne une étoile
       link: https://github.com/tomalaforge/angular-challenges
@@ -26,8 +26,8 @@ import MyIcon from '../../../components/MyIcon.astro';
 import SubscriptionForm from '../../../components/SubscriptionForm.astro';
 
 <CardGrid>
-<Card title="50 Défis">
-    Ce répertoire rassemble 50 Défis liés à <b>Angular</b>, <b>Nx</b>, <b>RxJS</b>, <b>Ngrx</b> et <b>Typescript</b>. Ces défis portent sur des problèmes réels ou des fonctionnalités spécifiques pour améliorer vos compétences.
+<Card title="51 Défis">
+    Ce répertoire rassemble 51 Défis liés à <b>Angular</b>, <b>Nx</b>, <b>RxJS</b>, <b>Ngrx</b> et <b>Typescript</b>. Ces défis portent sur des problèmes réels ou des fonctionnalités spécifiques pour améliorer vos compétences.
 </Card>
 
 <Card title="Subscribe to get notify of latest challenges">
diff --git a/docs/src/content/docs/index.mdx b/docs/src/content/docs/index.mdx
index afb2f50..60f3a6d 100644
--- a/docs/src/content/docs/index.mdx
+++ b/docs/src/content/docs/index.mdx
@@ -13,7 +13,7 @@ hero:
       icon: right-arrow
       variant: primary
     - text: Go to the latest Challenge
-      link: /challenges/signal/50-bug-effect-signal/
+      link: /challenges/signal/51-function-call-effect
       icon: rocket
     - text: Give a star
       link: https://github.com/tomalaforge/angular-challenges
@@ -27,9 +27,9 @@ import MyIcon from '../../components/MyIcon.astro';
 import SubscriptionForm from '../../components/SubscriptionForm.astro';
 
 <CardGrid>
-<Card title="50 Challenges">
-    This repository gathers 50 Challenges related to <b>Angular</b>, <b>Nx</b>, <b>RxJS</b>, <b>NgRx</b> and <b>TypeScript</b>.
-    These challenges revolve around real-life issues or specific features to elevate your skills.
+<Card title="51 Challenges">
+    This repository gathers 51 Challenges related to <b>Angular</b>, <b>Nx</b>, <b>RxJS</b>, <b>Ngrx</b> and <b>Typescript</b>.
+    These challenges resolve around real-life issues or specific features to elevate your skills.
 </Card>
 
 <Card title="Subscribe to get notified of the latest challenges">
diff --git a/docs/src/content/docs/pt/index.mdx b/docs/src/content/docs/pt/index.mdx
index 55abc3a..e399368 100644
--- a/docs/src/content/docs/pt/index.mdx
+++ b/docs/src/content/docs/pt/index.mdx
@@ -13,7 +13,7 @@ hero:
       icon: right-arrow
       variant: primary
     - text: Ir para o desafio mais recente
-      link: /pt/challenges/signal/50-bug-effect-signal/
+      link: /pt/challenges/signal/51-function-call-effect
       icon: rocket
     - text: Dar uma estrela
       link: https://github.com/tomalaforge/angular-challenges
@@ -26,8 +26,8 @@ import MyIcon from '../../../components/MyIcon.astro';
 import SubscriptionForm from '../../../components/SubscriptionForm.astro';
 
 <CardGrid>
-  <Card title="50 Desafios">
-    Este repositório possui 50 Desafios relacionados a <b>Angular</b>, <b>Nx</b>, <b>RxJS</b>,
+  <Card title="51 Desafios">
+    Este repositório possui 51 Desafios relacionados a <b>Angular</b>, <b>Nx</b>, <b>RxJS</b>,
     <b>Ngrx</b> e <b>Typescript</b>.
     Esses desafios são voltados para problemas reais ou funcionalidades específicas afim de
     melhorar suas habilidades.
diff --git a/docs/src/content/docs/ru/index.mdx b/docs/src/content/docs/ru/index.mdx
index e3f489c..79f2bd2 100644
--- a/docs/src/content/docs/ru/index.mdx
+++ b/docs/src/content/docs/ru/index.mdx
@@ -13,7 +13,7 @@ hero:
       icon: right-arrow
       variant: primary
     - text: Перейти к последней задаче
-      link: /ru/challenges/signal/50-bug-effect-signal/
+      link: /ru/challenges/signal/51-function-call-effect
       icon: rocket
     - text: Добавить звезду
       link: https://github.com/tomalaforge/angular-challenges
@@ -26,8 +26,8 @@ import MyIcon from '../../../components/MyIcon.astro';
 import SubscriptionForm from '../../../components/SubscriptionForm.astro';
 
 <CardGrid>
-<Card title="49 испытаний">
-  Этот репозиторий содержит 49 испытаний, связанных с <b>Angular</b>, <b>Nx</b>, <b>RxJS</b>, <b>Ngrx</b> и <b>Typescript</b>.
+<Card title="51 испытаний">
+  Этот репозиторий содержит 51 испытаний, связанных с <b>Angular</b>, <b>Nx</b>, <b>RxJS</b>, <b>Ngrx</b> и <b>Typescript</b>.
   Испытания основаны на реальных задачах или инструментах для того, чтобы прокачать вас.
 </Card>