Historical Rules · 30 September 2011
Rule 602.4
Official source text from the 30 September 2011 Rules release
Activating an ability that alters costs won't affect spells and abilities that are already on the stack.
Historical Rules · 30 September 2011
Official source text from the 30 September 2011 Rules release
Activating an ability that alters costs won't affect spells and abilities that are already on the stack.