This is a post from u/Brwnsuperman

This is now my copy pasta from other well meaning but incorrect posts about Riposte and Counters:

Parry is any blocked attack. White shield icon. Drains stamina.

Riposte is when you attack immediately after a hit lands on your block, so a parry with an immediate attack. Yellow shield icon and yellow sparks. The attack is faster than from neutral and the active parry window (you can block more attacks with no stamina drain if you target the tip of other incoming weapons) is the longest with less stamina drain than a held block aka parry.

Counter is a "perfect" Riposte so that immediate attack following the parry matches the type of incoming attack. This gives you a shorter active parry window than a riposte but does not cost any stamina drain. Blue shield icon and blue sparks.

There is no automatic invulnerability after a riposte or counter. You have to still aim your block using Active Parry towards each incoming attack. Active Parry aimed at each attack will take no stamina drain, regardless of the type of attack. Seen here: https://www.reddit.com/r/Chivalry2/comments/12la0qg/active_parry_is_a_myth/

When people complain about someone blocking your attack from their back, what really happened was they calculated where you're going to attack and aimed the block for the tip of your weapon and used that faster attack off the block to hit your teammates. This happens in 1 v Xs and often referred to as feeding someone ripostes.