Those can be really fun as they can turn the tide of battle easily if the correct conditions are met. Basically they all start out with one main side that you cast the card out as, and then when a condition is met the card will transform into a different card, typically one that is much stronger. Most of those cards are Werewolves that mostly just change at the beginning of each players upkeep if no spells were cast last turn, but there are also cards with different conditions such as http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=244740. This card starts out as a pathetically weak artifact equipment that costs a whole 7 mana plus it costs 1 mana to equip it and it only gives the creature +1/+0 so it's really just one extra damage and nothing more. That is until you hit your opponent directly with it at which point it will turn into a 13/13 Demon with Flying, Intimidate and Trample, a creature that is quite overpowered which excuses the high manacost. I myself used to run it in a deck I had that was largely based around getting the card http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=220154 on any one of my creatures and then protecting it with http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=220261 and buffing it with other equipment and enchantments.
I've had some fun with dual sided cards but I eventually just found them a bit bothersome to play with and they can be pretty unreliable if you're against an opponent that can counter the conditions of your dual sided cards transforming easily. And even then with a lot of dual sided cards being quite powerful on their own they are mostly all subject to removal as are most all cards so I don't like to depend too much on a few strong creatures rather than many small ones (which is why I don't play my http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=220154 deck anymore

).
I see.. Duel Sided Cards seems extremely weird (Like what if you're about to draw it- The opponent could see that you're about to draw that and possibly counter it before you even get it out)
Also, this could generate another problem- What if you don't have enough mana to use the Duel-Sided card? The other player(s) will obviously be able to see this card..
I also am looking forward to playing this with my friends (we have yet to set a date- they all bring their cards to school but I'm not doing this for a few reasons) one being I have a girlfriend... Who thinks its nerdy xD (Oh.. The secrets I must keep.)
I'm probably going to buy some of these new cards in the next week or two, after I work out all the current *problems* in my two decks, I need them to work correctly...
Now, I have another question: Am I, or am I not, Supposed to make a deck that "Smoothly fits together"- Such as having a deck with cards that promotes/helps another certain card? My decks are basically thrown together randomly (mostly making since to my play style of course)
My black deck consists of; http://gatherer.wizards.com/pages/card/Details.aspx?multiverseid=122406
, http://gatherer.wizards.com/pages/card/Details.aspx?multiverseid=2127
, http://gatherer.wizards.com/pages/card/Details.aspx?multiverseid=3857
,http://gatherer.wizards.com/pages/card/Details.aspx?multiverseid=129880
and
http://gatherer.wizards.com/pages/card/Details.aspx?multiverseid=220482
. Now, these are all mostly Randomly in there because they kind of all work good (and keep me alive)
Actually, The Doomed Necromancer & Beacon of Unrest work together well; as I only use these two if my
http://gatherer.wizards.com/pages/card/Details.aspx?multiverseid=146010 dies (or, as I've done before, Sacrificed for having too many cards in my hand, later drawing Doomed Necro, and reviving Doomgape to ultimately win).
Now, my Doomgape eats to heal at the start of my upkeep, so I do that. I don't use him unless I have
http://gatherer.wizards.com/pages/card/Details.aspx?multiverseid=142036 in my hand, as they work hand in hand for me. I heal with Doomgape at the start of the upkeep, eating whatever has a strong attack (depending on my health). Afterwords, I lay down Torment so the opponent (and myself) can no longer block or gain life, generally my Doomgape and whatever else is out can finish off my opponent and ultimately win the Duel for me- I do use caution before using this tactic, though.
Overall I am pretty proud of my black/green deck. I believe it helps me out very well and I wish I had a better Blue/Red deck
