The new mechanic that only activates if you have already played a spell this turn, so Goblin Retort summons 2 creatures instead of one for example. The idea behind this is playing cheap spells later instead of straight away.
1)http://www.mtgcardma...&set2=&setname=
2)http://www.mtgcardma...&set2=&setname=
3)http://www.mtgcardma...&set2=&setname=
Some quick and easy examples, I intend on making more complex cards using the followup mechanic in time.