Tools

The Ultimate Guide to Understand How Mod APK Games Work

Mod APK games
Written by Shusree Mukherjee

Android is currently one of the most popular mobile interfaces in the market. It is used by the majority of mobile companies and is well known for its diverse content and user-friendliness. Android applications such as Android games are used by millions of o fusers on a daily basis. One of the key factors that make Android applications popular is the high possibilities of modification. Let us first delve into what an APK file is, and how it can be used to modify and Android application.

What is an APK?

APK simply stands for Android Package File. It is essentially the packaging system that is used by the Android Operating system to install a particular application on your mobile phone. It is very similar to the .exe files that are found in our windows computers. Installing an APK file allows you to install an application without having to rely on any app store, such as the Google Play Store. Using an APK file is best-suited f the app you are looking to install isn’t present on the app store, or when you want to install an earlier version of the app.

Installing an APK file

It is fairly easy to install an Android game using an APK file. Simply go on to your web browser and download the appropriate APK version of the game you want to install. Next, make sure your device has an “install from unknown source” option enabled in the settings. After this, all that is left to do is hit the install button.

Important points of caution

A few things need to be kept in mind while installing an APK instead of using an App store to install an application.

  • Beware of malware: malware is often a common problem that accompanies downloading APK files from untrusted websites. Downloading an APK from such sites can infect your phone with damaging malware, causing loss of information or damage to the software.
  • Beware of illegal APKs: sometimes, illegal APKs of certain applications are available for download. These APKs allow you to use a particular game without buying it legally. This amounts to piracy and breaking of copyright laws and should not be practiced by anyone. It is, therefore, wise to always check the legitimacy of the APK file before installing it.
  • finding the right version: While downloading and installing APKs, make sure to install only the correct version. This is very important as your phone might not be supporting some of the older versions of the game.

What are Mod APK games files?

In simple terms, a modded APK is a modified version of the original APK file for an Android application. An APK file may be modified to add newer features or add an extra dimension to the utility of the application. The most common use of modded APKs is to bypass the paid components in an app. By using a modded APK to install an app, one can avail of the ‘premium’ features, which might have otherwise required payment. This is commonly seen in Android games, where users can often obtain the full version of the game without having to pay for it by using a modded APK file to install it.

An example of this can be an Android game that has its trial version free to play on the App store. Now, instead of the app store, a modded APK can be used to unlock this game completely, without paying for it, by installing it via the modded APK file.

Modded APKs are also used to change the game dynamics and add newer features. These can include the following:

  • New game levels
  • New skins and characters
  • Extra customization options
  • Addition of extra game content

Mod APKs are essentially handiwork of programmers who are looking to expand the horizons of your favourite mobile game. While some APKs might not be legal to use, others are legal customisations to an existing game.

How to mod an APK game file

An APK file consists of all the relevant files required for the installation of the game, compiled in a binary format. It is not simple to change an APK file, as each application and game has a specific checksum and signature. These become invalid once the APK file is modified.

So how does one mod the APK file for an Android game? 

This is done by changing or modifying certain files inside the compiled APK file. These changes manifest themselves into the working of the game and add the extra features that you were looking for while modding the game. Some commonly modified components of an APK file are:

  • Images and skins used in the game
  • Styling resources
  • Game environment resources
  • Files included in the assets folder
  • Files containing configuration data
  • Character resources of characters used in the game.

Once you have decided which components of the game you want to modify, you can begin with the process of modding the APK.

Softwares required for modding an apk

You are likely to require this three software at the minimum to efficiently mod the APK file of a game. It is, therefore, essential to check whether or not you have all of them installed.

  • The latest Android version
  • Java 7
  • Windows 7 (preferably higher version)

So what are the basic steps?

Well, the primary steps of modding any application consist of three steps:

  1. Making the right modifications to the files compiled inside the APK.
  2. Applying the appropriate signature.
  3. Successfully installing the APK

If you can complete all of these three steps successfully, and get your desired result while running the game, your modding effort has been a success.

Making the change in the game resources

The first step in changing the resources inside the APK is opening the APK file through WinZip or a similar application. If you’re unable to do so, you might need to change the APK file’s extension.APK to the .zip in order to open it with WinZip.

After you have accessed the files, proceed to make the appropriate changes in resources with the help of packager tools. Packager tools have the further advantage of allowing you to make the necessary modifications to the game files without having to unpack all the files. After changing the necessary resources, the next thing to do is make the appropriate changes to a signature file in the APK file.

To this, the first step is to delete existing signature files inside the APK file. The existing signature is present in a META-INF folder. On this folder, the .RSA and .SF files contain the signature, Dara. Delete these files to eliminate the existing signature.

Add a signature to the APK game file

The next step is to add your new signature to the APK file. This step is essential because an APK that is not signed cannot be used to install a game on an Android device. Signing involves applying the default certificate signature to the APK.

The steps of applying a new signature to the APK file are as follows:

Generate a new certificate: the Java system is the most ideal for creating a new certificate for your APK. The Java interface comes with JDK, which is used to generate the signature certificate. The key tool included with the JDK is the tool responsible for signing the APK. You can check the command online, but before executing the command, one should always check the parameters to be defined under the command.

The Keystore command is used for determining the name for your Keystore. On the other hand, the alias command is used for setting a random name for the alias. The alias is used to recognise the certificate. The validity function is used to determine the figure of days that the signature is valid. The standard setting for the validity function is 1000 days. After executing the entire command, the Keystore file gets generated and can be seen in the file directory.

Onde the certificate has been generated, you can easily proceed to sign the document. First, make sure no existing certificate is left to be deleted in APK. After this step, use signing tools such as the tool Jarsigner for signing the document.

Like while generating the certificate, some parameters might be required to be adjusted before executing the command. The Keystore function is used to enter that name, which you have allocated the whole generating the certificate. Next, the app name function is used to denote the APK file name that you wish to sign. Alias command is used to enter the alias that you have denoted while creating the certificate.

The success of the execution of the command can be checked by looking for the CERT.SF and CERT.RSA files under the META-INF folders.

Installing APK on phone

The signed APK can now be used to stall your modded game on the Android device by a process known as sideloading. The command to be used for installing the modded game is the ‘adb’ command. An adb command allows you to execute commands on your mobile phone through your PC. To initiate the process of installation, firstly, your phone needs to be connected to the PC via a USB cable.

The adb.exe file stands for Android Debug Bridge. It can be used to initiate operations on the Android interface or transfer files. The adb.exe file intimates the following command:

That is – adb install <appName>

The app name function is used to denote the name of the APK of the game to be installed. If all the previous steps have been followed correctly, a “success” message should be displayed.

Legal issues

One of the most common issues that a modded APK can face is the issue of legal copyright infringement. Certain countries have strict rules against copyright infringement and prevent any sort of modification to standard APKs. For example, in the USA, the DMCA has laid down strict guidelines regarding the protection of intellectual property. This is responsible for the strict fines for ant modifications to standard android games, that is levied on modders.

In Europe, the protection of copyright rights regarding android games is under the EU copyright directive. A famous example of the application of this law was when a 22-year-old man was convicted in the United Kingdom for selling a modified Xbox console. This set of rules extends to Android software and games as well. A common infringement that is prevalent in both the EU and USA is the modification of Android game APKs to make them free of cost to use. This is a common bypass of paid applications and is severely punishable under the copyright laws.

There have been, however, exceptions to this strict ruling against copyright infringement of modders. In countries like Spain and Italy, major console companies such as Sony have lost copyright infringement cases, based on the argument of personal freedom of the console owners to modify their owned devices. This has been extended to Android games as well, where modified games have been declared ‘legal’ based on their personal use only, and no intent of distribution.

Modding is a common phenomenon in the Android gaming industry. It is done by developers as well as independent modders to improve games as well as add newer features to existent games. By following the prevalent legal boundaries, it is safe to mod any given game. Successful modding requires following easy to follow steps, which most layman can perform after some practice.