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I googled to death and ended up finding a third party program to make mouse buttons bindable to use as attack and other things. The program is called x-mouse. It is extremely useful, not only with Unepic, but with anything where you want to customize things. Just set your buttons on your mouse to "simulate keypress" and choose which key you want it to simulate, when you press it it will be just like pressing the button on the keyboard. It works without lag and makes this game much more playable and comfortable with keyboard+mouse. This and my other fix should be stickied.