There are more than one way to win a game of Scrolls. In Magic the Gathering, you can divide decks into four main categories based on how they aim to win the game: aggro, combo, control and tempo. If we want to establish possible deck types for Scrolls, this seems like a good place to start.
For each of the deck types borrowed from Magic, I'll briefly explain how it aims to win, discuss how the differences between Magic and Scrolls impacts the deck's viability and also provide you with an example deck list.
Let's get started, shall we? Fun? Fun! :)
An aggro deck aims to win by using creatures to deal enough damage to win the game as fast as possible, ignoring its opponent and their strategy as much as possible.
Sligh was one of the pioneer aggro decks in Magic, introducing typical aggro features such as the mana curve and using direct player damage for the finishing blow.
Aggro is actually not a very viable archetype in Scrolls, mostly due to the fact that most creatures only attack every other turn and that you need to deal 30 damage (10 damage to three idols) instead of the 20 life in Magic. It is too hard to get enough damage in before the opponent can establish control and clear the board with Quake, Thunder Surge or similar, and late game aggro hasn't got enough power per scroll to compete.
Another difference between Magic and Scrolls is the lack of mulligans in Scrolls. This hurts earlygame decks more than lategame tdecks since it is hard to fix your hand by sacrificing for scrolls when you need to ramp up your resources instead.
As an example aggro deck, GO Joes is an aggressive Growth / Order deck that operates mostly on only two Order and two Growth and has Decimations for finishing the opponent (mimicing the burn finishers of Sligh):
A combo deck aims to win by using a combination of two or more scrolls that interact to produce a powerful effect that can win the game outright or produce a game state that will lead to a victory eventually.
A traditional combo deck in Magic is a cousin to aggro where the plan usually is to assemble and fire the combo early enough that the opponent doesn't have a chance to bring their own plan into action. Prosperous Bloom was one of the first combo decks and could kill regularly on turn 7 but later combo decks where much more powerful, some even being able of first turn kills with the right draw.
Most of the combo decks of Magic win by either setting up a combo that can convert cards into mana and then cast draw spells to fuel the combo or by creating an infinite loop that yields damage, cards or life from every iteration.
In Scrolls, no combos exists that can go infinite and there are very few ways of generating extra resources during your turn (Nutrition is about the only example). Instead, the closest to a non-interactive combo that Scrolls has is one-shotting an idol with combinations such as Copper Automaton - Iron Whip - Magma Pack or Kinfolk Veteran - Focus - Unleash Inner Power.
Currently, it is not practical or feasible to pull off three-scroll combos three times before the opponent either kills you or assembles enough defense to thwart the combo. However, with new scrolls being added, there is a possibility that a combo will be found later on that will make the deck type viable.
As an example combo deck, Eye of Copper is a bursty but unreliable triple resource deck aiming to one-shot idols:
A control deck aims to win by stalling out the game for long enough that it can win by playing more and better scrolls than its opponent.
Ever since Brian Weissman's "The Deck", control decks have been very prevalent in Magic. Control decks in Scrolls operate a bit differently than in Magic though. Unlike in Magic, there are no way to counter threats as they are being played in Scrolls. Additionally, very few ways to directly attack your opponent's assets (resources, scrolls in hand or in deck) exists in Scrolls.
Instead, control decks in Scrolls mainly focus on the board and clearing your opponent's units from it, either on a 1-for-1 basis or through powerful board sweepers, such as Quake and Thunder Surge. To do this effectively, control decks usually need ways to accelerate their own resources while slowing down their opponent long enough that the superior drawing and scroll quality of the deck can turn the game around. Once control is established, killing the opponent is usually a formality that can be accomplished in many ways.
Control is a very viable deck type in Scrolls. The slower pace of Scrolls compared to Magic (attack only every other turn, 30 damage needed etc) allows enough time for control to set up and stall out the game to a point where it can take over and win.
GE Sweeper is a Growth/Energy control deck that combines the direct damage removal of Energy with the scroll quality of Growth (Kinfolk Veteran, Quake, God Hand) and powerful drawing (Fertile Soil / Clockwork Library):
A tempo deck aims to win by establishing and maintaining a pace in the game where it will deal enough damage to win before its opponent can.
Where aggro decks are all about winning as fast as possible and control decks are all about winning slowly, tempo decks are really about winning just fast enough. This is usually accomplished by efficient creatures (usually on the lower end of resource costs) and spells that dirsupts the opponent's game or removes potential blockers so that steady damage can come through, eventually winning the game if the pace can be maintained.
A hybrid of aggro and control, the tempo deck type has been around in just about every modern format in Magic. Traditionally, the slightly slower but more powerful cards of tempo decks gives the deck a very good matchup vs pure aggro decks.
Tempo decks in Scrolls are very powerful, potentially the best deck type in the game. This is mostly because of the countdown mechanic and the slower pace compare to Magic allowing the game to drag on for long enough that players have to interact with each other, and interaction is usually where the tempo deck shines. Also, due to the "sac a scroll to draw two" mechanic, tempo decks don't necessarily need to play draw spells to be able to play at least two efficient threats each turn in the midgame which might be very hard for aggro decks to push through and for control decks to deal with efficiently.
MO Tempo plays a ton of efficient creatures that excels in interacting with opposing creatures (especially through Spiky) as well as efficient, but not necessarily permanent, ways to move blockers out of the way such as Pushback and Pother:
Combat, unit values, units attacking, and units being attacked is explained in this guide aimed at new players.
How to deal with the hard trials in Scrolls when you have a small library.