If you are using a generic controller, you will probably face the following issues:
1. Controller not recognized by game,
2. Controller is recognized and able to control the character, but the button bindings are all wrong,
3. In-game prompts are showing button1, button2 etc. instead of ABXY.

But don't worry, I am here to help you out :)

Step 1:
Go to this link[www.gamepressure.com]and download the patch files. It says ACII but it is AC1 compatible.


Step 2:
Extract the files (x360ce.ini & xinput1_3.dll) to the game folder. If you do not know where is your game folder, right click on AC1 in the Steam library>properties>local files>browse.


Step 3:
Make sure your controller is connected to your PC and recognized by Steam. Then, launch Big Picture Mode on your Steam Client (at the top right corner).


Step 4:
Go to settings (top right corner), then click on Controller Settings. Make sure you controller is detected by Steam. Then, check Xbox Configuration Support and uncheck Generic Gamepad Configuration Support.


Step 5:
You can exit or stay in Big Picture Mode, that doesn't matter. Again, make sure your controller is connected to your PC (you cannot launch the game first and connect controller later). Then, you can launch the game.

Step 6:
At the game menu, go to Options>Customize Controls. You can see the model of your generic controller being written at the left hand side. And the prompts have been changed to Xbox prompts (ABXY).


Now you can enjoy the game with your controller! I hope this guide helps you :)

Please remember that this guide is for those who are using a generic controller. If you are using XBOX One controller, u should probably skip step 3 and 4. If you are using a PS4 controller, I am sorry that I can't help you, but I believe there's a PS4 prompts mod on NexusMod.

If you are playing ACII, you can also follow this guide.