Introduction[]
Hi, it's Hamengeri with a quick blog post. I decided to post something like this, because we all have or had some concepts and it would be cool to have them in one place - both for us, players and possibly a Rioter with absolutely no inspiration. I'm also curious what lurks in your void-consumed souls.
If there are any suggestions somewhere on the wikia, please link them in the comments section and I will link them on the list. If you have an idea, you can post it in a comment and I may add it.
Thank you for already shared suggestions.
Actual list[]
1. Shopping frenzy[]
A game mode that would enable some of old items and allow us to buy items from different maps.
2. Time travel: Champions[]
A game mode that would allow us to play pre-rework version of champions, small refactors included, nerfs not. I could play the true Karma once more.
3. Ability draft[]
I'm almost sure everybody knows what it is. You pick a champ, then you pick abilities like champions in draft mode. It would be hard to implement - every skill would need alternate costs and ultimate version (for purposes of 
Karma's 
Mantra and company).
4. Hunger games[]
Explained with details here.
5. Double the...[]
Gamemode where something is doubled - for example items or champion abilities. Examples here and here.
6. Class Is Out![]
Each team bans an entire class of champions prior to Blind champion select, suggested by Empty.
7. Dominion/Classic crossovers[]
Dominion versions of classic maps, suggested by Lykrast.
8. V-Zero[]
Details here. It's quite hard to explain this shortly.