In Naraka: Bladepoint there are two types of weapons, melee and ranged. Melee weapons can perform standard attacks or focus attacks. Standard attacks will not produce any visual effect while focus attacks will create a blow glow on the character.
Both of these attacks can be countered. Standard attacks can be countered simply by using another standard attack while focus attacks require the use of a parry. When fighting, it is best to use a mix of these attacks in your combos to avoid being predictable.
When two standard attacks collide with one another, they will clang and both characters will throw their weapons in the air and back up. To counter focus attack, you must parry the attack by pressing both of your attack buttons. This will create a red aura around your character and the enemy will be throw to the ground.
In addition to being knocked down, the enemy will also drop their weapon. This allows you to steal their weapon and possibly leave them defenseless. You can also follow up with a combo while they are prone and catch them when they stand up. Parrying correctly requires precise timing that can be different for each melee weapon.
For more information on Naraka: Bladepoint, check out Where to get dandelions in Naraka: Bladepoint and Where to find Shadow Bushes in Naraka: Bladepoint on Pro Game Guides.