Counter Hits
A counter hit occurs when you strike your opponent during their startup frames.
Counter Hit Benefits
The biggest benefit counter hits give is +2 frame advantage on moves, allowing new links and more damaging combos. In addition, counter hits give a move a 20% damage bonus. For multi-hitting moves the properties can vary per move. For example with Ryu's b+HK Axe Kick it normally does 40*40 damage for a total of 80 and is +4 on hit, and on counter hit it does 50*40 damage for a total of 90 and is +6 on hit meaning while the damage bonus only applied to the first hit the advantage bonus applied to both. However Ryu's f+MP Collarbone breaker which does 30*30 for 60 damage and is +1 on hit does 36*30 for a total of 66 damage but is still only +1 on hit.
Crush Counters
New to Street Fighter V are Crush Counters; these are similar to the Fatal Counter system in games like BlazBlue an Persona 4 Arena. Each character has a variety of moves that when they land as a counter hit, they will cause a special hit effect with a loud "explosion" noise, and cause special effects such as causing the opponent to crumple forward, spin backwards, or go flying into the air often allowing follow up combos. These moves are typically on HP and HK; either standing, crouching, or as a command normal. Universal to everyone is the crHK sweep, which will cause a hard knockdown forcing the opponent to do a delay rise, giving plenty of time to either form a setup or activate resources such as Alex's V-Skill or Ibuki's Kunai Reload.
In addition to the larger combo opportunities, Crush Counters generate V-Gauge; the amount generated depends on the move and character.
New in Season 3 is a universal adjustment to Crush Counters, which causes the combo to be scaled more heavily. Crush Combos start the combo at 2 hits instead of 1, meaning the next hit will cause 80% damage instead of the normal 90%, the third will cause 70% instead of 80%, and so on. Because of this other counter hit combos will often cause more damage but not give the V-Gauge gain.
Armored Moves
Certain moves in Street Fighter V have a property called Armor. Armor allows the character to absorb an attack, without being interrupted. Common examples of this are Laura's EX Bolt Charge, Urien's specials after activating his V-Skill, and Abigail's HP while in V-Trigger 1. When absorbing an attack the damage it would normally inflict is instead converted into grey life. Armored moves are typically EX Specials or V-Trigger bonus, however certain normals such as Zangief's charged HP have it as well.
Most armored moves can only absorb 1 hit of any type of attack, meaning many EX Projectiles such as Ryu's EX Hadoken will still beat them. However some can absorb multiple hits of armor. Abigail's EX Nitro Charge can absorb 2 hits while in V-Trigger, and his Metro Crash in V-Trigger 2 can absorb up to 99 hits when at maxed charged making it nearly impossible to break through.
Armor breaking moves are much rarer in Street Fighter V than IV. Any CA will break armor, and a couple of character specific moves such as Ed's V-Skill will break armor.
Moves that are armored have a special red hit effect when they absorb an attack.
Reversals
Pre-Jump Frames
Landing Recovery
Wake Up Options
Projectile Invincibility
Damage Scaling
Priority System
New to Street Fighter V is the hit priority system. In Street Fighter 4 when two moves landed on the same frame and neither has invincibility, both players would take damage regardless of the strength of the move; the stronger move would cause more damage and have more advantage but still be hit usually meaning he cannot continue a combo afterwards. In contrast, Street Fighter V uses a hit priority system where if two moves land on the same frame, the higher strength move will win. A simple example is a 5f medium punch that is +1 on block. Pressing MP twice will cause a 4f gap; in Street Fighter IV the opponent could press a 4f light attack and trade, sacrificing health to get out of pressure or secure a win if the opponent is at low enough HP. In Street Fighter V however since medium is higher than light, the medium attack will beat the light attack with the Ryu player taking no damage. Further, it will count as a counter hit allowing bigger combo opportunities. Because of this it makes getting out of block strings and pressure in general much more difficult, and playing the neutral game scarier.
The priority system is easy to remember: mediums and heavies beat lights, heavies beat mediums, and specials beat normals. When two buttons of the same priorities collide, they will trade as in Street Fighter IV without any benefits.