In a discussion I had with another judge about oppressive rays, but google search results are giving me mixed feedback.


Card Name:
Oppressive Rays
Mana Cost:
White
Converted Mana Cost:
1

Types:
Enchantment — Aura
Card Text:
Enchant creature
Enchanted creature can't attack or block unless its controller pays 3.
Activated abilities of enchanted creature cost 3 more to activate.


Mana abilities are activated abilities that do not use the stack. As such, Generator servant is the opposing card in question:


Card Name:
Generator Servant
Mana Cost:
1Red
Converted Mana Cost:
2

Types:
Creature — Elemental
Card Text:
Tap, Sacrifice Generator Servant: Add 2 to your mana pool. If that mana is spent on a creature spell, it gains haste until end of turn. (That creature can attack and Tap as soon as it comes under your control.)


If I have a generator servant enchanted with oppressive rays, can I activate the ability of generator servant and not pay 3? I have been getting asked by many people about this interaction and am having a difficult time with it.
Why or why not, and what ruling citation can I look at for further clarification?

You can't.

Oppressive Rays has nothing to do with whether activated abilities use the stack or not. It simply adds {3} to the cost to activate the ability, i.e. what is on the left of the “:”.

So for the Generator Servant, its ability will read:

{3}, Tap, Sacrifice Generator Servant: Add 2 to your mana pool. If that mana is spent on a creature spell, it gains haste until end of turn. 

If you can't pay the full cost, you can't activate it.

Daniel Kitachewsky
L4, Paris, France
Rules NetRep