Priority

Priority confuses many players. It's simple to explain and apply, but hard to understand.

Basically, when a Monster is summoned, the turn player has priority to activate an Ignition Effect or a Spell Speed 2 or higher effect. When a Chain resolves, the turn player has priority to activate a Spell Speed 2 or higher effect.

For instance, when you Synchro Summon Brionac using Blackwing - Blizzard the Far North and Shura the Blue Flame as Synchro Materials, you, the turn player, have priority to activate an Ignition Effect or a Spell Speed 2 or higher effect.

Brionac's effect is an Ignition Effect, so you could use your priority to activate it on the summon. However, you could use the Ignition Effect of another card, such as a Destiny Hero Malicious that is in your Graveyard or a Blackwing - Gale the Whirlwind that is on your side of the field. What I'm trying to say is that you don't have to use the Ignition Effect of the Monster you just summoned; you can use any one Ignition Effect.

Of course, you could also use your priority to use a Spell Speed 2 or higher effect. For instance, you could use priority to activate Super Polymerization from your hand in response to the summon, fusing your Brionac and your opponent's Elemental Hero Stratos to Fusion Summon Elemental Hero Absolute Zero.

However, if a Trigger Effect (or a Trigger-like effect) would activate in response to the summon, then you would not be able to use priority to activate an Ignition Effect. In this case, the opponent of the player who the Trigger Effect belongs to will have priority to respond.

Let's say you Synchro Summon Brionac using Plaguespreader Zombie and Goblin Zombie as Synchro Materials. As soon as Brionac is summoned, Goblin Zombie's Trigger Effect activates, assuming it was sent to the Graveyard. Goblin Zombie's Trigger Effect prevents you from using a Spell Speed 1 Ignition Effect (like Brionac's), and since the Trigger Effect was yours, your opponent gets priority to respond with a Spell Speed 2 or higher effect.

What would happen if you were to Normal Summon Blackwing - Gale the Whirlwind while your opponent has Stumbling on the field? Stumbling's Trigger-like effect will activate in response to Gale's successful summon, and you could not be able to use Gale's Spell Speed 1 Ignition Effect. However, since it was your opponent's Trigger-like effect, you are given priority to respond with a Spell Speed 2 or higher effect.

One more thing that you may want to know about priority:

The turn player basically has priority any time when the opponent does not. The turn player's opponent would only have priority when the turn player passes it to them, which would include when:

-the turn player activates an effect; priority would be passed to the opponent to give them a chance to respond.
-the turn player moves from one Phase to the next.
-the turn player verbally passes priority to the opponent; this usually occurs when the turn player does not want to use an Ignition Effect on the summon of a Monster (for example, Zombie Master), but is not limited to this.

Well, I hope you all enjoyed, or at least understood a portion of, this lesson in priority. If you have any questions feel free to ask.