Your guardian angel. This is a godsend to have equipped, but an absolute pain in the arse to overcome if you're the aggressor. Countless times have players been saved from certain death by this armour. If you get it, hang on to it like no tomorrow!
What it does:
Every time there is a need to use DODGE 闪, EIGHT TRIGRAMS can automatically use DODGE for you. Judgement needs to be passed for it to work. If the judgement card is a red suit (hearts or diamonds), the attack is automatically dodged.
How to use it:
Simply equip it during your turn by placing it next to your character card. The player must bear in mind that it is his or her responsibility to use the EIGHT TRIGRAMS. If the player forgets to flip a judgement card and instead uses a DODGE card, too bad suckerrrr!!! Of course, how anal you want to be about rules of engagement is up to the players to decide. The caution here is that many players tend to completely forget that they even have EIGHT TRIGRAMS equipped and are too quick to flash a DODGE card.
Note that you can use the EIGHT TRIGRAMS to auto-dodge when RAINING ARROWS 万箭齐发 has been used by another player against you. This is because RAINING ARROWS requires a DODGE, and EIGHT TRIGRAMS can do just that.
Younger Zhu Ge Liang 卧龙诸葛亮 has EIGHT TRIGRAMS equipped by default as long as he does not have any other armour equipped. This makes the character unfairly powerful in my opinion, but the fear of this character usually prompts everyone to kill him first anyways.
Zhang Jiao 张角 is able to use his "Lightning Bolt 雷击" ability when the EIGHT TRIGRAMS auto-dodges for him. This makes the combination of Zhang Jiao equipped with EIGHT TRIGRAMS are ridiculously deadly combination.
Although it is listed as an "armour" in the San Guo Sha 三国杀 card game, the words 八卦阵 actually refers to a military formation used in the Three Kindgoms Era. Zhu Ge Liang's successor, Jiang Wei 姜维, once challenged his enemy counterpart Deng Ai 邓艾 to a military formation showdown. Jiang Wei won but both of them have a fair amount of respect for each other. Another depiction is the Stone Sentinel Maze 石兵八阵 laid by Zhu Ge Liang to trap Lu Xun 陆逊 after the Battle of Yiling 夷陵之战. Either way, both really should not have anything to do with the ability to auto-dodge, but its a fancy armour to have in the game anyways.