Trinisphere and Engineered Explosives

[Atwa]

Question:

My opponent has a trinisphere and I want to play an Engineered Explosives without counters, so I can destroy his Chalice.

I only have coloured mana.

Can I play Explosives without counters, while paying the 3 extra mana for Trinisphere with colored mana?

Thanks.

[Ewokslayer]

No, with Trinisphere in play, Explosives costs 3, for each colored mana of the 3 mana used to pay Explosives costs it has a charge counter on it.

[Atwa]

That sucks.

Thanks anyway.

[Nightmare]

A little extra info. Your opponent has a Chalice for 1, Chalice for 2, a Trinisphere, and a Nimble Mongoose in play (what deck runs those, doesn't matter). You want to deal with the Mongoose, and only have access to colored mana. You can do it, by adding three mana of a single color to your mana pool for Explosives. The Sunburst sees 1 color, so sets it at one. The X value is 3, making it get around Chalice, and the Trinisphere is satisfied.

If it was a Goyf, you could pay 2 mana of one color, and one of a second color to do the same.

If your opponent has a chalice for 0, you can pay a colorless to make the CMC 1, and blow up the chalice with sunburst = 0.

[Atwa]

I knew all that, I just ran into this guy with trini and I scolded at him for being wrong.

After the game I strarted wondering and now it turns out I was wrong :(

Can't have a perfect knowledge of the rules after all :)