Converge

Converge is an ability word introduced in Battle for Zendikar, which highlights spells whose effects depend on the number of colors of mana you spend to cast them. 
==History==
Converge was designed as a counterpoint to the colorlessness of the Eldrazi in Devoid and colorless mana. It took inspiration from Domain and Invasion block though not Sunburst, which had a similar premise potentially from <c>Emblazoned Golem</c> specifically. It was one of the first cards to care about spent mana color and the first to care about all five equally.
The key difference between the similar Sunburst and Converge is that the first is a keyword with a static ability which was only permitted on artifacts while Converge is an ability word. Converge could thus invoke any form of scaling effects and could be on other nonpermanents.
While Converge (6) ranked lower than Sunburst (9) on the Storm Scale, it fell to most of the same traps. The block was not set up to support four-to-five-color decks and in fact fought against it with Oath of the Gatewatch's colorless mana requirements. Between Sunburst and Converge, only three spells with mana value two were ever made, and those at four or greater were barely useful at three colors, showing the shallowness of options. It avoided having design rigidity problems by having it be an ability word, but it was still difficult to design, develop and track, on top of being unpopular. Rosewater opined that it had a better shot if the set better supported the mechanic.
Converge also appeared in Commander 2016 (<c>Crystalline Crawler</c>) and in a cycle in Modern Horizons 2. <c>Chamber Sentry</c> and <c>Springmantle Cleric</c> have Converge-like abilities. 
==Rulings==
* You are limited to the mana cost of each spell. You can't use more (colorless) mana.
* If a spell with converge on the stack is copied, it's just created on the stack. No mana was spent to cast the copy, so zero colors of mana were spent to cast it.
==Examples==
==References==