I know that cheating is a bad act, but I’d like to know what the ruling of Islam is about it?
In fact, is it a haram (forbidden) act or it is solely a Makruh (disapproved) practice?
Is there any tradition in regards to this?
Cheating is a kind of "lie". The Qur'anic verses (ayahs) and traditions prohibiting "lie" are free from any stipulations so the word "lie" embraces all kinds of "lie" whether it is a verbal lie or a written lie or a practical lie especially when it results in trampling others' rights.
إِنَّما يَفْتَرِي الْكَذِبَ الَّذينَ لا يُؤْمِنُونَ بِآياتِ اللَّهِ وَ أُولئِكَ هُمُ الْكاذِبُونَ
Verily, those who forge lies they are Those who do not believe in Allah's Signs and Revelations and they are Indeed the liars. (Al-Nahl 105)
إِنَّ اللَّهَ لا يَهْدي مَنْ هُوَ كاذِبٌ كَفَّارٌ...
... Indeed Allah does not guide someone who is a liar and an ingrate.(39:3)
Imam Muhammad al-Baqir (a.s.) says:
“Certainly Allah has created the lock for every evil and the key to all these locks is drinking wine. But lying is worse than drinking.”
Additionally, there is no difference among the scholars about prohibition of cheating. To find out about it in details please visit this LINK.
Cheat and Trick are forbidden in Islam and blameworthy not characterized by the believer!
وعن أبي هريرة رضي الله عنه أن رسول الله صلى الله عليه وسلم قال: " من حمل علينا السلاح، فليس منا، ومن غشنا، فليس منا" ((رواه مسلم)).
The Messenger of Allah (Peace be upon him) said, "He who takes up arms against us is none of us; and he who cheats us is none of us." [Muslim].
This applies to all Cheats and trickery in any field and in the right of any person as evidenced by the words of the modern.