Due to their high numbers, the Skeleton Army is effective against slowly attacking, single target, and high hitpoint enemy troops such as the P.E.K.K.A. or Giant.
Another benefit is the Skeleton Army's cost of 3 Elixir, making it a very versatile card that can give you an Elixir advantage in almost any case. (Most tanks will be killed for a 1-5 Elixir advantage, mini-tanks are Elixir neutral.)
They are also useful for countering building targeting troops such as Giants and Hog Riders if they are by themselves.
Despite being incredibly susceptible to area damage, the Skeleton Army is capable of countering Wizard, Witch, Bowler, Princess, Ice Wizard and sometimes Bomber at tournament standards. The Skeleton Army must be placed directly on top of the unit, however.
However, Skeleton Army can counter directional splashers for a positive elixir trade if placed directly on top of the splasher. This means it can take out Wizard, sometimes Witch, and Bowler. However, your skeleton army must be one level higher than the Witch to take her out.
Other swarm troops such as Barbarians and Minion Horde may be more favorable, as they have higher hitpoints compared to the Skeleton Army.
The Skeleton Army can force the enemy to use their splash spell, allowing you to deploy other swarms of low hitpoint troops to deal high damage. However, this may not be wise because it generally costs less Elixir to destroy the Skeleton Army than deploying it.
Zap, The Log and Fire Spirits are the best as they give an Elixir advantage. Arrows and Bombers give an even Elixir trade. Using Poison or Fireball will incur a 1 Elixir loss against yourself. Using a Valkyrie, Witch or Wizard, while being themselves 1-2 Elixir higher than the Skeleton Army, they will generally be at full health after eliminating the Skeleton army, so may not be a negative trade. Spear Goblins can also be used against a "lone" Skeleton Army that is on your side of the arena. However, at tournament levels, Spear Goblins can not be used to eliminate the skeletons. A level 10 Spear Goblin is needed to one-shot the skeletons from a level 1 Skeleton Army.
The Skeleton Army is not recommended to use offensively, as they can be easily wiped out with spells such as Arrows, and are most effective as a distraction.
Keep in mind that, if by some chance the Skeleton Army manages to get on a tower, it will deal extremely high damage or even destroy it.
If the opponent has left the game, a Skeleton Army can do immense damage to Crown Towers, without being countered by other opponent troops.
The Skeleton Army is best paired with troops like Witch, Prince, or any other troop with high damage. It can also be used to protect a P.E.K.K.A., Royal Giant, or another heavy troop when attacking.
3 Skeletons cost 1 Elixir, while 14 cost 3. Playing the Skeleton Army profits 5 more Skeletons at the Skeletons card's Elixir rate. However, splash units and spells can still easily end them.
It can be used as a lure for the opponent's Zap or Arrows before you throw a Goblin Barrel. This won't work, however, if the opponent has a way to take out your Skeleton Army and/or Goblin Barrel (such as a mirrored Zap or Arrows). Also, in either case, you'll be losing plenty of Elixir, meaning it may not be a very good strategy.
During Double Elixir time, the Skeleton Army can be used to great effectiveness if the opponent is forced into wasting their area damage cards. You can play the Skeleton Army along with Rage as this increases the Skeletons' attack as well as travel speed, leaving little room for the opponent to counter.
In general, the Skeleton Army should not be used to counter cards that deal Death Damage, as the death of the latter card will often result in only 3-4 skeletons surviving, although this will usually give you a positive Elixir trade (a large 5 Elixir profit if used to counter a Golem, 3 Elixir extra for Giant Skeleton).
Skeleton Armies are not a good counter against themselves unless one is 1 level higher. However using a Skeleton Army on your side to counter an invading one can help clear it, with no elixir loss.
Using a Rage on the Skeleton Army makes it a huge threat since they are already fast movers and hitters; this now makes them more deadly, and also Mirroring the Skeleton Army gives a huge numbers advantage. However, raging and mirroring the Skeleton Army is very risky if the opponent has area damage cards, and can result in a significant Elixir loss.
An Ice Golem would be able to eliminate the entire Skeleton Army with its death damage at tournament levels. Hence it can be used as an expendable counter to the Skeleton Army for a 1 Elixir advantage.
The Skeleton Army can be an excellent card to play on the opponent's side if the player has knocked down one of their towers. If they play a tank or mini tank in the corner nearest their King and remaining Arena Tower and the Skeleton Army there immediately after, the Skeleton Army will split three ways with one portion going toward the Arena Tower and two sets taking different paths to the King Tower. If the opponent does not respond with a centrally placed ground unit or building, the Skeleton Army will do great damage to all targets, and will not be as susceptible to area spells as it normally is because of the split.
Another strategy is to split the Skeleton Army between both lanes by placing it behind the King's Tower, and putting a tank/mini tank such as a Knight or Valkyrie in front of it to push both lanes, as having the high damage per second skeletons on both sides means that they are not as weak to splash damage. This can be countered by cards such as the Valkyrie, Baby Dragon or Bomber placed in the center, as the skeletons are usually close to the tank due to their high speed.
The Skeleton Army was released with Clash Royale's soft launch on 4/1/16.
The Skeleton 'Larry' in the Skeleton Army's description is a reference to the Clash of Clans commercial, Larry.
It has the highest overall damage per second of any troop card, and the second highest overall DPS in the game. When all of the level 8 Skeleton Army's skeletons are damaging one target, it does a staggering 1372 DPS.