A Normal Summon ( 通 ( つう ) 常 ( じょう ) 召 ( しょう ) 喚 ( かん ) Tsūjō Shōkan "Normal Summon", or simply 召 ( しょう ) 喚 ( かん ) Shōkan "Summon") is the simplest way to Summon a monster. The turn player can perform a Normal Summon during their Main Phase when the game state is open.
In OCG text, "Normal Summon/Set" would be referred to as 通 ( つう ) 常 ( じょう ) 召 ( しょう ) 喚 ( かん ) , while "Normal Summon (but not set)" would be referred to as only 召 ( しょう ) 喚 ( かん ) .
To perform a Normal Summon, the player simply plays a monster directly from their hand into an available Main Monster Zone in face-up Attack Position, declaring that the monster is being Normal Summoned.
After each Normal Summon, a Summon negation window opens, and either player may negate the summon. If not, the summon is considered successful, and the Summon Response Window opens, and each player, starting from the turn player, may respond to the summon. If no action is taken, the game state becomes open again.
In addition to the "Normal" Normal Summons, are three sub-categories.
Instead of Normal Summoning a monster in face-up Attack Position, a player may instead play that monster defensively by "Set", placing the monster in face-down Defense Position.
The turn player can only Normal Summon or Set once per turn, and only once that turn. Monsters cannot be Normal Summoned in face-up Defense Position, unless stated otherwise.
For monsters that are Level 5 or higher, you must Tribute at least 1 monster you control before the Normal Summon/Set. This is called a Tribute Summon. Monsters that are Level 5 or 6 require 1 Tribute and Monsters that are Level 7 or higher require 2 Tributes.
If you Tribute Summon in face-down Defense Position, it is called a Tribute Set. A monster Tribute Set on the field is NOT considered Summoned.
Gemini monsters are a type of monster that are treated as Normal Monsters on the field, but they can be Normal Summoned again while already face-up on the field to make them Effect Monster and "unlock" their effect(s). (This Normal Summon counts as the player's one Normal Summon/Set per turn). If the monster in question is Level 5 or higher, no tribute is required for the second Normal Summon.
While a player may only perform 1 Normal Summon/Set per turn, there are three types of "Additional Normal Summon" effects which can increase this limit. [1]
These effects simply set the Normal Summon/Set limit to a fixed number. They do not stack, and the one that grant the highest number will apply (e.g. If a player applied both the Effect of "Double Summon" and "Chain Summoning", the limit number would be 3).
These effect gives the player additional Normal Summon/Set limit, but the player can only gain these effects once per turn. So, even the player applies multiple of these effects, they will get a total of 1 additional Normal Summon, the change is that the player has wider set of eligible monsters to be summoned this way.
However, these effects will stack with the first group. (e.g. They player may apply the effect of "Double Summon" and "Swap Frog", and they can Normal Summon/Set twice this turn due to the former. They can also Normal Summon 1 "Frog" monster in addition to the limit due to the latter, making the summon limit 2+1, or simply put, 3.)
These effects outright perform a Normal Summon, and the action does not count toward the turn's Normal Summon/Set limit. Player must outright perform the Normal Summon (or Set, if applicable) immediately after that effect resolves.
