Collective Effort

Mana cost: {1}{W}{W}
Type: Sorcery
Set: Eldritch Moon Promos #17s (rare)

Escalate—Tap an untapped creature you control. (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Destroy target creature with power 4 or greater.
• Destroy target enchantment.
• Put a +1/+1 counter on each creature target player controls.

Collective Effort has 10 printings, first in Eldritch Moon (2016). EDHREC ranks it #3,203 among Commander cards. It appears most in Tidus, Yuna's Guardian decks (10,753 on EDHREC). 4 public decks on TCG run it. It has 9 official rulings.

Legality

commander: legal
legacy: legal
vintage: legal
pauper: not legal
modern: legal
pioneer: legal
standard: not legal
brawl: legal

Public decks that run Collective Effort

Counter Blitz - Final Fantasy Commander, led by Tidus, Yuna's Guardian
Forces of the Imperium - Warhammer 40,000 Commander, led by Inquisitor Greyfax
Rebellion Rising - Phyrexia: All Will Be One Commander, led by Neyali, Suns' Vanguard
The Fantastic Four - Marvel Super Heroes, led by Mister Fantastic

Commanders that run Collective Effort most

Deck counts from EDHREC.

Often played with Collective Effort

Cards that show up in the same decks on EDHREC.

Rulings

2016-07-13: Effects that reduce the cost of spells reduce the total cost, including any escalate costs added.
2016-07-13: You choose all of your modes at once. You can't wait to perform one mode's actions and then decide to choose more modes.
2016-07-13: If one target of an escalate spell becomes illegal, the other targets will still be affected. If all of the targets become illegal, the spell won't resolve.
2016-07-13: If you choose the first and third modes, and destroying the creature ends an "exile until" effect (such as that of Lunarch Inquisitors), the creature will return to the battlefield before you put +1/+1 counters on creatures. The same is true if you choose the second and third modes and destroying the enchantment ends such an effect.
2016-07-13: You can't choose any one mode multiple times.
2016-07-13: Additional costs don't affect a spell's mana value.
2016-07-13: You can tap any untapped creature you control to pay the escalate cost, including one you haven't controlled continuously since the beginning of the turn.
2016-07-13: If an effect allows you to cast a spell that has escalate without paying its mana cost, you pay escalate costs for that spell if you choose more than one mode.
2016-07-13: If two of the chosen modes of an escalate spell target a creature, you may choose the same creature for each mode's target, or choose different creatures. The same is true if the chosen modes target a player (or opponent).