First Strike
The First Strike is a technique used in the Paper Mario titles and the Mario & Luigi titles. Bosses, mid-bosses M. Bushes and Hurt Plants cannot be harmed by usage of a First Strike, with the exception of Paper Mario: Sticker Star's Big Cheep Cheep in Surfshine Harbor. In Paper Mario, Goompa first mentions this to Mario as they walk through Goomba Village. To do a First Strike, Mario can simply jump on the enemy, hit it with his Hammer or with an attack from one of his partners, depending on whether or not the enemy has spikes. The First Strike helps Mario in battle, as it allows him to damage or drain all HP from an enemy before taking a turn.
The First Strike can also be used against Mario by enemies. For example, if a Koopa Troopa successfully attacks Mario with its shell, Mario will get hit by the First Strike and take damage. Monty Moles are very skilled at making the First Strike by trying to throw rocks at Mario. First Strikes from enemies can be avoided by dodging the attack or by using the Chill Out badge.
In Paper Mario: The Thousand-Year Door, Mario will do a First Strike with an Action Command, doing more damage and possibly defeating weak enemies, such as Goombas and Dull Bones.
First Strikes in the Mario & Luigi titles are similar to Paper Mario's First Strikes with one key difference – a first strike on one enemy in the field will damage all enemies in the battle. However, in Mario & Luigi: Superstar Saga and Mario & Luigi: Partners in Time, the First Strike with a hammer works differently. When Mario or Luigi hammer an enemy on the overworld, all enemies in the battle will become dizzy. In Mario & Luigi: Bowser's Inside Story, Mario & Luigi: Dream Team, and Mario & Luigi: Paper Jam a First Strike with a hammer will instead damage all enemies. Bowser can also use First Strikes by punching or breathing fire on the enemy.
Enemies can also do first strikes to one of the characters. If the enemy or one of its projectiles hits a character in the back, they trip and cannot get up until it is their turn or if they are damaged by an attack.
In Paper Mario: Sticker Star, a First Strike has an added mechanic. By collecting HP Pluses, the Hammer and jump power will increase every time when the one's digit is at a zero from five. Also instead of going in battle (if enough power), the enemy will be killed and will drop a coin.