What it does
Web-slinging is an alternative cost introduced in Marvel's Spider-Man set. When you cast a spell using its web-slinging cost, you pay a reduced mana cost but must also return a tapped creature or artifact you control to its owner's hand as part of the cost. This lets you "swing" a card back to hand to cheat out something more efficiently.
The common mistake is overlooking the "tapped" requirement—the permanent you bounce must already be tapped when you announce the spell. You can't tap something just to enable this; it needs to be tapped through attacking, abilities, or other means first. Also, web-slinging is optional; you can always pay the normal cost instead.
In Commander, it rewards aggressive or tap-heavy builds, letting you replay value creatures or untap-payoff permanents while discounting big spells. Sequence your attacks and tap effects beforehand to unlock it.
