Vigorous Opposition

Vigorous Opposition is an Achievement/Trophy in BioShock Infinite. The Achievement is worth 10 Gamer Score and the Trophy is bronze.

Requirements
The player will have to kill 75 different enemies of any kind either directly via a Vigor or while they're effected by one.

Strategy

 * Play on the Easy difficulty level to kill enemies easier.
 * Upgrade Possession with the Possesion Aid upgrade, which will cause Columbia Citizens, Soldiers and Beasts to commit suicide once the Vigor's effect runs off, giving the player an easy kill.
 * Several Vigors have a more damaging effect after being upgraded, so it is recommended to upgrade them.
 * To save Salts or to achieve this Achievement/Trophy quicker, the player can abuse the games check point system. Find a location with enemies, perform Vigor set of the Vigor traps until your Salts run out and reload the check point to start over, until you have achieved the Achievement/Trophy. Some great locations for this are:
 * The Patriot's Pavilion of Soldier's Field. There are several Soldiers conveniently lined up in this area, which is reached right after getting the Bucking Brunco Vigor.
 * The Good Time Club of Finkton. After entering the club, set traps in front of the closed curtain, as several men will come running out when they open.

Behind the Scenes

 * The Achievement/Trophy icon depicts a Vigor bottle with a human skull on it.