So this is a pretty typical B(lack)G(reen) Elves/Gilt-Leaf Tribal deck with lots of synergies. I have not unlocked even a quarter of all cards yet so there is definitely room for improvement with this one and I might update it as I get new cards.
You win either by slowly overwhelming the enemy with a metric shit ton of tokens, trampling them with a big creature (e.g. Jagged-Scar Archers+Wildsize or Nissa's -7 ability), combat tricks (attacking with many creatures & casting Primal Bellow on an unblocked one) or dealing lethal damage with Shaman of the Pack.
This deck hopefully also serves to show that one can already play decks other than aggro in the versus multiplayer and be successful. I have won more games with this deck than I have lost in multiplayer so it's already viable even in this early, less than perfect stage.
(external list: http://deck.tk/3kbG6UiM)
1 Thornbow Archer
2 Primal Bellow
1 Might of the Masses
3 Bone Splinters
2 Scarred Vinebreeder
3 Gatecreeper Vine
1 Elvish Visionary
1 Gather the Pack
2 Lys Alana Scarblade
1 Nissa, Vastwood Seer
3 Jagged-Scar Archers
2 Reclamation Sage
1 Shaman of the Pack
1 Nissa's Pilgrimage
1 Dwynen, Gilt-Leaf Daen
4 Lys Alana Huntmaster
1 Llanowar Empath
1 Chorus of Might
1 Gilt-Leaf Winnower
1 Kothophed, Soul Hoarder
2 Woodland Cemetery
4 Golgari Guildgate
60 cards in total.
Now, as for each individual card (I'm not gonna mention the obvious Tribal synergies of most cards):
Thornbow Archer: One drop for some early damage and also nice due to its forced 1dmg that can be a permanent substitute for Trample if he's pumped up enough to survive the attack.
Primal Bellow: Pumps your creatures and, as mentioned before, can be used effectively in combat to deal lethal damage late game by casting it on an unblocked creature. Keep in mind that only FORESTS count, so no dual lands or Swamps.
Might of the Masses: Same as Primal Bellow except that it works best when you've got a lot of creatures.
Fog: Prevents all combat damage and either saves your ♥♥♥ or allows you to do otherwise risky attacks that would (for instance) leave your flipped Nissa unprotected.
Bone Splinters: Good removal.
Scarred Vinebreeder: Nice way of recycling your dead elves to get some use out of them still :)
Gatecreeper Vine: Chump blocker and essentially a fetch land. If you have two Swamps already then focus on fetching Forests to make Primal Bellow as effective as possible.
Elvish Visionary: Card draw. Play more if you can.
Gather the Pack: Card draw, specifically creatures (useful for getting the creature you need in that moment ... or Nissa if all is well already). Best wait until its Spellcraft requirement is met before using it. If it ends up puting elves into the graveyard anyway you can at least make use of them with Scarred Vinebreeder.
Lys Alana Scarblade: Removal and a way to sometimes capitalize on discard effects from your opponent (i.e. voluntarily discard cards that way if you would be forced to discard all elves in your hand anyway).
Nissa, Vastwood Seer: Decent planeswalker with card draw and creature summoning. Try to play her only when you can flip her in the same turn since she is very susceptible to removal. Also, most of the time it makes sense to go for her ultimate before summoning the legendary.
Jagged-Scar Archers: Gets bigger the more elves you have and shoots down flyers. Win/win.
Reclamation Sage: Destroys artifacts and enchantments, useful against a lot of decks. If not, just discard him with Lys Alana Scarblade to remove some creature.
Shaman of the Pack: As mentioned above, try to hold on to this card until you can deal lethal damage with it (or enough to finish off the opponent by other means that turn).
Wildsize: Pump, trample, card draw. Great card.
Nissa's Pilgrimage: Effective fetch land with or without Spellcraft. Nice to get enough land for an early Nissa flip.
Dwynen, Gilt-Leaf Daen: 3/4 with Reach, +1/+1 for all Elves and some lifegain ability. Great card, use twice if you can.
Lys Alana Huntmaster: Creates tokens for synergy effects, best when on the battlefield multiple times.
Llanowar Empath: Scry and creature fetch, cf. Gather the Pack.
Chorus of Might: Like a fusion of Might of the Masses and Wildsize, just without the card draw. As mentioned above, can be a game finisher.
Gilt-Leaf Winnower: 5/3 Evasion (Menace) and Removal. Play twice if you can (maybe instead of a Bone Splinters).
Kothophed, Soul Hoarder: All around great black card. 6/6, Flying, card draw (based on ANY permanent going to the enemy's graveyard). Just make sure you have enough life left before playing him since otherwise your opponent might just use him against you.
The mana base could be too small for comfort for some of you but having played this a lot I'm confident that it works most of the time. 22 lands are okay in my eyes seeing how you've got mana acceleration and a lot of one-drops in there. But feel free to experiment.
Last but not least ...
... thanks for viewing! Leave feedback if you want to but please keep in mind that I KNOW that this could be better, it's just that I have a rather limited card pool right now. As it changes so might this guide.
Also, because of that this is more of a template so figuring out how to make this work differently with your own card pool and play style preferences is not only possible but encouraged!
Source: Guide by Demut- http://steamcommunity.com/sharedfiles/filedetails/?id=492623165