Special effects are a way to visually reproduce peculiar situations, generally as regards the supernatural side of the show. Jack Lynch was the special effects coordinator on Salem set, while Matthew Mungle was the prosthetic makeup artist.
One of the main approach to storytelling of the co-creators and executive producers Adam Simon and Brannon Braga was to redefine a genre. To do so, they decided to avoid falling into the horror narrative clichés made of spooky effects and leaps in the dark. They were also adamant that realism for special effects was imperative. 
CGI special effects are used moderately on the show, for succor wherever the prosthetic makeup is unable to make at best the effect.
- The black veins that appear when a dark force is at work. We find examples of such veins during Mary Sibley's deal with the Devil, and later as a side effect of shamanic ritual performed on John Alden.
- The morphing abilities used by witches to transform fingernails into claws or turn a toad into an owl.
- Countess Von Marburg's horribly disfigured visage. This was achieved with computer-generated imagery along with her self-moving relic.
- The power to project fire from a witch hands or handling hot coals is another example of the use of CGI special effects.
- The final fight scene between Mary and Countess Von Marburg in Season Two has been slightly retouched with CGI special effects to delete the support cables used to simulate the flight. Same applies any time a levitation phenomenon or wall crawling has been shown.
- Telekinetic abilities, especially when they have to break or magically fix a glass or a mirror. Otherwise, the computer graphics only removes the supports that allow the levitation effect.
- The Sentinel appearing as a swarm of insects was also made with CGI special effects.
Prosthetic makeup is undoubtedly the most used way to get special effects on the show. This is due to the fact of desiring a realistic effect in the interpretation of the various characters.
- Spectre and Hags are achieved by a long process that saw the creation of prostheses applied on the whole body of stunt actor. This is then molded and reassessed as the prostheses are worn, to facilitate the movement.
- Same goes for Mercy Lewis' severely burned body during the second season or for the crags corpses.
- All familiars have a prop counterparty or even more than one depending on usage. While Mary's toad is simply a replica made of skin-safe silicone rubber, Brown Jenkins prop is constituted by a series of three pieces with different measures and parts. A first prop is constituted for two-thirds by a reproduction of the back of a rat while the front part (the "head") is a just a rubber plug; the second prop is made only by the legs and tail also with a rubber plug on the front; the third prop is only a plug with a tail. All this serves to give the impression of swallowing the rat with precise camera games.
- On twitter, Ashley Madekwe who plays Tituba said that it takes over an hour to do the scars all over her face and chest. Prosthetic flaps covered her own eyes so vision was limited. 
- Despite what repeatedly stated, the second and third seasons of Salem contains inconsistencies with the desire to avoid CGI effects as much as possible. Mary Sibley throwing fireballs out of her hands is one of the clearest examples of a more mainstream inclusion of special effects as used in other TV shows related to witchcraft and magic.
- ↑ Adam Simon and Brannon Braga about the decision to use practical effects over CG made effects
- ↑ Ashley Madekwe about her season 3 make-up