I call it all purpose because it uses cards that are versatile with multiple uses or purposes.
I also tried to make it balanced offensively & defensively.
At first glance this deck doesn't look like an all purpose deck as it lacks any damage spells. But that is where the versatility of the cards comes into play.
Card Versatility Guide:
Graveyard: GY is more versatile than most realize. Not only does it tank longer than any other remote-tank, it can shred towers & pumps faster than any other card when paired with the right cards & played at the right time.
The reason I stick with Graveyard as a main win condition over other cards like the Balloon or other building targeting win conditions like Golem & LH, is because GY can be played as an active defensive play, meaning the skeletons will actually serve a purpose on defense. Cards like Golem, LH, Loon can only be played on defense passively, since none of those cards can fight back, all they can do on defense is to distract or kite.
Electro-Wizard: I chose for its versatility. He has the spawn zap giving you a swarm killer without having to occupy a card spot with Zap, Arrows, etc., EW gives you both the cheap swarm killer you need and an actual troop to defend or attack with after you use him for Zap. EW in this deck needs to be played 95% of the time as a Zap card. Don't waste his Zap unless it's a critical situation on defense.
Ice Wizard: Another Anti-Air option as having enough air defense cards is imparative. He's also cheap, deals splash, and can slow an opponent's push allowing your other troop cards more time to go to work on killing them.
Lumberjack: Again another versatile troop. Decent HP, very fast rate of attack, decent damage. And he great to use for fast tanking quicker cards, then dropping rage upon death, giving you the opportunity to rage out your push. He's also a great defensive card and tank killer. He's also good on pushes literally pushing a tank then helping clear a path for a tank with his fast attack rate.
Giant Skeleton: In this deck, Giant Skeleton is not a primary win condition, or even a secondary one. Only us him offensively on counterpushes, because in this deck Giant Skeleton is the Defensive Centerpiece. GS can occupy enemy troops and distract them from your tower. He keeps enemy troops busy giving your troops time to assist GS on defense, plus when he dies he drops the biggest push killing bomb in the game. When counterpushing with GS you can drop GY to tank for him & LJ to push him towards their tower faster. You can also drop other troops like DG or EW to help kill troops trying to stop GS from getting in Bomb Range of their tower.
Freeze: Freeze is the dirtiest card in the game, especially when Leveled up. In dire situations it can be played on defense if you actually have enough elixir to play counter troops to help kill their push when you froze them.
I only play freeze when I have a Graveyard Combo set up.
1 example of a GY Combo is playing GY after dropping a Battle Ram behind your KT, when the Battle Ram passes your princess tower, you drop GY, then wait for your opponent to drop their counters before you drop freeze on their troops & tower, allowing Battle Ram to connect for charge damage, while GY skeletons are surrounding their tower.
Dart Goblin: Cheap, anti-air, long range, fast rate of attack. Can be used for chip damage as a throw away cycle card, or used to assist pushes.
Battle Ram: Secondary win condition. Also very useful on defense. When you add up the HP of both Barbarians with the HP of the Ram = 2,687 HP for a Level 12 BR. That is a ton of HP for only a 4 elixir card. The next card that has more total HP is Royal Hogs that cost 1 more elixir for just over 3000 HP. But Royal Hogs cannot fight back on defense, and they run so fast that they'll run right past your opponents troops and out of kiting range making them useless as distracting or kiting defensive plays.
The main strategy is to not push at all in the first 2 minutes. Only defend, and only counterpush if you made some positive elixir trades from defending. Try and build up positive trades so that when double elixir time starts you can afford to build a large push and defend when or where needed. Often times just building a large push in double elixir time, will clog up the lane, basically acting as a proactive defense by keeping their troops busy & occupied.
On defense use Giant Skeleton or Battle Ram on your side to tank damage while your other troops take them out from a distance.
This deck basically has four spells.
Electro-Wizard's spawn Zap.
Lumberjack's death Rage
There's no deck where you can get away with having 4 spells and have it be an actual good deck, unless it's a troop carrying a spell, which is basically like having 2 cards in 1. With this deck it's like having 10 cards vs you're opponents 8 unless they're using spell troops as well.
Cards with similar value & versatility as troops with spells are cards with 2 stages.
Which this deck has 2 of those card types in Giant Skeleton's Death Bomb, and Battle Ram's 2 Barbarians
On top of all the value and versatility those 4 cards provide, every card in this deck can be used on defense.