Genesis Chamber Trigger

[Ekann1]

Normally I'm not on the posting side of the rules question, but this is more tournament rules-ish which I don't know. So, here goes.

I'm playing at a Competitive REL event (a GP) with untapped {Genesis Chamber} out. My opponent casts a creature. Say, {Delver of Secrets}. I know you're required to remind people of some triggers but not others. (Something to do with triggers that are good for them or not?) I don't think I have to remind my opponent to get a Myr, but since I control the permanent I'm not so sure. Could I get some help here?

Thanks.

[rarehuntertay]

From what I understand, you cannot forget your triggers. An opponent is not required to remind you of your triggers

[Remillo]

Since you control the permanent, it's your trigger.  You're obligated to remind your opponent about the trigger, since you control it.  If a judge is called on it, you'll probably get a warning for missed triggers because it's a detrimental trigger, as it does something bad for you.  Then again, it's up to the judge, but be wary about it.

[rarehuntertay]

http://www.wizards.com/magic/magazine/article.aspx?x=mtg/daily/feature/233

[Ekann1]

Thanks guys. That's not what I wanted to hear, but is good to know. +1s all around.