Building, Defenses, and Structures - Upgrade Priorities

     We have all had that moment, you know the one...its one of those moments when you look back and say "If I could go back, I would have done this this way or done that that way".  Most of us never heard or even thought about using forums, guides and blogs back when we were a low Town Hall, and because of that we probably made quite a few questionable choices in our upgrades hierarchy.       We probably upgraded our goblins before any other troop; thinking that since it helps us get the loot, it must be the most important troop...well now we know better, but unfortunately we can't go back in time and change those choices.  On the other hand, if you are actually playing through your first account with Clash of Clans and somehow found your way here, congratulations!  You are about to learn what to upgrade when, and why you should do it that way, so that you will never look back and have that moment of regret.


Defenses

     Your defenses will always be a priority when looking at what to upgrade next.  In general, you want to have your defenses upgraded as high as possible as early as possible when you upgrade your TH level, and you don't want to upgrade your TH until your defenses are upgraded to max level or at the very least within one level of maximum.  There are exceptions to this strategy though, most of which have to do with war (which we will talk more about later in this post).

Early in the Game (Low TH Levels):

     When you are early in the game and your TH is still low level, your upgrade priorities are a little different from later on in the game.  At lower levels, your mines and elixir collectors (and later, your dark elixir drills) will contribute the majority (or at least a large portion) of the resources you gain in the game.  Because of this, you will want to upgrade them as high as you can, as early as you can.  You will be glad you did after you see the difference it makes in the amount per hour they can produce, it makes a significant improvement in how much you can gain in a day's time.
     Once you get your heroes, you will want to begin upgrading them as soon as possible, and try to keep one of them upgrading at all times.  You're probably thinking this sounds nuts because the heroes are so expensive, and it is difficult to save up when you first become able to raid for it, but the reason I say its good to begin upgrading them as soon as possible is that in total it will take 227 days to reach the max level of 40 on each of your dark elixir heroes.  So the way I see it, the sooner you start, the better, not to mention this can give you a leg-up on the competition since most players put off upgrading  their heroes until later on when they can acquire and save up dark elixir more easily.  This will really shine in wars, when you will be expected to attack the member on the opposing clan that is supposed to be your equal, and upgrading heroes is not weighted nearly as heavy as upgraded defenses are, so you will not be moved up the war ranks by upgrading heroes, making your war targets much easier to defeat. 

* For more on the heroes, read the posts about the Barb King and Archer Queen.    
(Also refer to the * at the bottom of the page for information about upgrading spell factories and laboratories)    

     Next, you will want to upgrade your defenses, and I recommend splash damage defenses first, since they are the most effective at taking out hordes of barbs, archers, and goblins, and this is what you will face most of the time.  So upgrade your mortars first, then your wizard towers, then any traps that do splash damage (like bombs and big bombs).  After all that, you can upgrade point defenses like cannons, archer towers, and air defenses.  Once you start being able to build and upgrade hidden teslas, you can include them with the other point defenses in your upgrade priority hierarchy. 
     After the defenses are upgraded, you will want to upgrade your walls.  The level of your walls makes a huge difference in how hard it is for attackers to get to everything in your base.  Early on they won't even have wallbreakers, but even when they do have them, they will only be able to break through 2-3 layers of walls max (if they know how to deploy the wallbreakers properly).  After that it will be up to their troops to fight through each layer of walls to get to each enclosure, and higher level walls equals much more time spent hitting walls and likely getting wiped out by defenses before they can get to too much of your base.
     When you have upgraded your other structures, you can upgrade the air sweeper and any barracks you still need to upgrade.  When you are still working on upgrading your barracks and dark barracks to get new types of troops, you will move them up the priority list so that they are one of the first things you upgrade.  But after you have at least one of them maxed out, your barracks can be moved down on your priorities list unless you need more to be able to make the armies you want faster, but that decision is all up to you. 

Later in the game (later TH levels):

     At later TH levels, your heroes should still take priority but the mines, collectors and drills should be maxed out.  If they are not, go ahead and get them all maxed out (the drills especially may need upgraded because they cannot get maxed out until TH-10).  Keep in mind that your heroes can only be leveled up to 10 at TH-8, but at TH-9 you can upgrade them all the way to level 30.  This will take quite some time, so get to work on them as soon as possible, because if you can get them to level 30 you will have a huge advantage over other TH-9's because very few of them will wait, and will go to TH-10 with level 15-20 heroes or even lower.  (Also refer to the * at the bottom of this post for more information pertaining to upgrading spell factories and laboratories)
     Your splash damage defenses will still be high on the priority list, but will now fall behind upgrading your heavy defenses, such as your X-bows and Inferno Towers.  These defenses have high damage output, and also have high hit points, so they really add a great deal to the difficulty level of 3-starring your base or stealing your resources.  They are expensive and take a long time to get upgraded, so get to work on them early on.  Once you get them upgraded however, your base will look much more imposing, and the site of fully upgraded inferno towers and x-bows will send many would-be attackers running for the hills! 
     Once your heavy defenses have been upgraded, your next project will be to work on your mortars and wizard towers.  Since these cause splash damage (and wiz towers are very useful for protecting your resources from large numbers of smaller troops), they will be more useful in most cases than the point defenses.  You can also take on a strategy of upgrading 1-2 splash damage defenses and 1-2 point defenses at a time, so that you are upgrading them simultaneously.  This will make it take longer to finish both kinds of defenses, but it allows them to both be upgraded at the same time. 
     If you choose to focus on your splash defenses, finish them off then begin upgrading your point defenses.  These defenses are great at working down giants and other high hit point troops because while they can only focus on one target, they have a higher damage output than splash defenses.  Upgrading all of your cannons, archer towers and air defenses (all your point defenses), will significantly increase your base's ability to deal with giants, golems, and PEKKAs.  The air defenses will be able to quickly take down any level air troops, even dragons and lava hounds when they are maxed out, and players with these kinds of armies will notice this when they are deciding whether or not to attack you.  When you add in the fact that your infernos and x-bows are already upgraded (or should be), your base will be very hard for players to have any success against, no matter how strong they are. 
     The rest is basically the same as with lower THs, and a lot of it is left up to your preference.  If you want to be able to make dragons, PEKKAs, witches and lava hounds in all your barracks and dark barracks instead of just being able to make them in one of each type of barracks, you can work on upgrading them next.  If you would rather get those air sweepers and your traps upgraded, go for that next.  It really all depends on what you feel will help you the most at that time. 
     Now it comes time to start on those walls.  They should already have been at the max level for the TH level below you, so you should only have to upgrade each wall 1-2 levels to once again max them out.  At these later levels, the walls get extremely expensive and it can take a very long time to upgrade them all completely.  To help with this, the game begins allowing you to choose to use gold or elixir to upgrade each wall starting at level 8 walls (the black walls with white skulls).  Since it will take so long, you may be best served to go ahead and start upgrading your walls as soon as you run out of other critical upgrades that cost elixir (like troop upgrades and any essential barracks or storage, lab, or spell factory upgrades).  This way, you won't be sitting there upgrading walls and have everything else already finished. 

* It should be noted that at both low and high TH levels, you will include your Laboratory and Spell Factory in the top of your upgrade priority list.  These should preferably be upgraded as soon as you can afford to do so, because upgrading these buildings will give you access to new spells and upgrades for your spells and troops.  Since upgrading troops and spells in your laboratory will not take up a builder, you can do the troop and spell upgrades without slowing your progress in upgrading your defenses and other buildings.  There is much more information about this in the post titled "Spell Factory and Dark Spell Factory - Upgrade Priorities".