This can be a nice idea to introduce non-friendly clan wars among clans. It will be the same way as the friendly clan wars. Clan leader or co-leader can challenge any other clan for a clan war. There should time limit 2 days (1 preparation day and 1 battle day). It is different from normal clan wars because the players already know which clan is to be their opponent. But the war win bonus awarded to players, is divided by 2 in this type of clan war. This is to prevent clans from challenging too often.
Advantage over friendly and normal wars : This type of war can be an advantage over the others as clan members already know about their opponent and it is better than friendly wars because it will award war bonus, loot and clan xp. (Friendly wars don't give back the elixer spent in attacks and donations, so they are not promoted).
Match-making : For match making, the level of the opponets defences can automatically be adjusted to match-make. This way, it will be more effective.
For example, there are two clans, clan A and clan B. The topmost member of clan A is TH 8 maxed but the topmost member of clan B is TH 7 maxed. The level of the defences of TH 8 maxed are brought down to TH 7 . This way it is possible for both of them to 3 star their mirror.
Guys, feel free to make changes in this idea. This can really be good but some changes might be needed. I want your help guys, to make it a part of clash of clans.
Thankyou.



