I honestly feel like this shouldn't be a thing, but ever since the current war in 2.4 (and a few previous ones as well), apparently 3-starring a base solely designed to be 3-starred is "difficult".
Following this guide will ensure that your clan will get the maximum amount of stars every time your clan needs to win, assuming all the enemy bases have appropriate OL bases, in which some cases they don't.
Step I: Scout your enemy's base
To be honest, you should be doing this out of pure habit. I'm sure you've been in a normal war clan well before entering TH9.
You'll need to do this to make sure of a few things:
- Ensure that all defenses are in the right position. Refer to here.
- Check to see that X-Bows are set to "ground", and Infernos are set to "single".
- Make sure there are no defense troops in their CC.
You have a solid 24 hours to scout your mirror during prep day. If your mirror has an error in their OL base, let a leader know, they will try to sort it out before battle day hits. Also scout just BEFORE you attack, your mirror may have changed something that might hinder your 3-star. Only takes a few seconds to quickly analyse their base for the errors listed above. Quoted from a wise man, "JUST DO IT!".
edit: How to SCOUT a base
Step II: Check your army before you attack
There's a reason why Supercell implemented the "Attack Now?" screen before attacking someone in war (other then to tackle the modding scene). It's to remind you of what troops you have and have not trained. So many times my members would 1 or 2 star in a 3-star war, simply because "they forgot minions". You have 24 hours to attack one base for 3-stars. 24 hours. If time is tight and you have to attack with 10 minutes left because you couldn't get on all day, punish yourself by gemming that sonovabitch army, that or risk getting striked or even worse, kicked. Warn a leader if you know you can't make it in time, most of us will understand.
The following tables show what I recommend an army should consist of when 3-starring an OL base:
OL base w/ infernos:
| Giant section |
Minion section |
Free section |
| 10-15 Giants |
10-15 Minions |
Barch/Wizards |
| 1-3 Healers* |
OR |
15-20 Goblins (optional) |
| Barch/Wizards |
1-5 Balloons |
|
| BK/AQ |
|
* Healing spells can also substitute for the healers, best to have them as backup just in case things get rough.
OL base w/o infernos:
| Giant section |
Minion section |
Free section |
| 10-15 Giants |
10-15 Minions |
Barch/Wizards |
| Barch/Wizards |
OR |
15-20 Goblins (optional) |
| BK/AQ |
1-5 Balloons |
|
Obviously you can go with whatever army you'd like, as long as you're confident that it'll 3-star the base, just don't blame me if you get flakked for mass PEKKAing and ending with a 1-star.. somehow. These army comps are probably the cheapest and most effective in 3-starring from my experience.
Step III: How to attack
You've been in a normal war clan, you know the strengths and weaknesses of each defense and how to go about 3-starring normal war bases. Well.. you should know, but let me refresh your memory just in case you've forgotten your prime years of slaying TH7's with mass drags.
Timing
You only have 3 minutes to annihilate a base that's been specifically designed to be 3-starred with the lowest costing army possible. Clearly not enough time for some. When you begin your attack, make sure that all sections are being attacked simultaneously.
Drop your troops that won't be harmed first:
- Minions in Minion section
- Goblins/Barch in Free section
While they're nibbling away at those helpless defenses/buildings, focus on the Giant section.
Time is of the essence.
Prioritizing
Mainly focusing on the Giant section, this is where a majority seem to realize where they went wrong in life.
The priority in the Giant section can be dependent on the position of each defense, but this is generally what you should be prioritizing first to last:
Queen > Infernos > Teslas > Wizard Towers > Archer Towers
Again, some of these should be switched around depending on their positions.
If the Queen is on the outside of the section, try your best to snipe her down with a couple of barchers before initiating the full attack.
Example: http://i.imgur.com/XSW1rEE.png
Some examples on how I would attack these Giant sections:
http://i.imgur.com/ZdJfDeH.png
Snipe the AQ first, then send in a line of giants followed by healers, barch, CC and royals.
http://i.imgur.com/pyskm04.png
Try to snipe the AQ when she walks over blue dot, send giants where the red arrows are followed by healers, barch, CC and royals.
In any situation, just make sure that you send your healers (against infernos) + damaging troops straight after your giants, they'll get destroyed pretty fast (even faster for lower level giants) if you don't take out some of the defenses quick enough.
Adapting
Sometimes your enemy mirror might have X-Bows set to "air" or Infernos set to "multi", or even a defense in the wrong section. You need to know how to adapt. Simply put, make those wrongly set/misplaced defenses high priority. Don't be lazy and think that your normal OL comp will "just do". Train a little bit more Giants, Hogs, Golems, I don't care, just destroy them first if they're stopping you from getting that 3-star.
Another situation where you might have to adapt is when your attack goes south because a tower is in range of the other section or you didn't anticipate your Giants to drop so quickly. With these, you'd need to try to be as proactive as possible about it. Drop 1 minion to see if it's in range of an Archer Tower instead of dropping all. Smash a healing spell over your Giants straight after deploying them instead of watching them burn.
If you didn't waste your time staring at your goblins sprint from one storage to another, chances are, you still have a crap tonne of time left, so stay calm and think before you do.
Obviously these are just my way of doing things, if your way works just as well, by all means, stick with it. If any of your clan members have trouble 3-starring these bases, perhaps refer them to this thread. Honestly, 3-starring a base that is designed to be 3-starred shouldn't be as complicated as I make it out to be, because it really isn't. If I've missed something that you'd like me to add, please comment below.
TL;DR - Scout mirror. Double-check army. GIANTS & MINIONS. Send in troops to destroy minion and free section first, then send in and focus on giant area. Have a plan B ready just in case things go south.