Characters can Guard by holding down the guard trigger. Guarding will prevent all damage from all attacks from all directions while the guard trigger is held, but will not prevent the character from being grabbed. Every attack in the game deals a certain amount of damage (unique to that attack) to a characters guard. This damage remains throughout the entire round and is communicated through the color of the blockstun particle effects.
Green - Barely damaged guard
Yellow - Moderately damaged guard
Red - Severely damaged guard (in danger of breaking)
When a character's guard has taken damage equal to their guard's maximum health, their guard will break and they will be briefly stunned, unable to take any action. After a stun a characters guard health is reset to full.
Damage dealt to a characters guard slowly deteriorates while the character is not guarding.
The amount of guard damage a character is able to sustain before being stunned is character specific, with puppet users having the lowest guard health in the game.
Supports and shurikens deal neglibile guard damage.
Guarding during certain actions result in a Guard Cancel.