Just an idea I know other games do this as well and while it wouldn't hold any Gameplay value it would bring a new feel to the Rift I feel add some sounds for the corresponding cycle (owls,ravens growls from the jungle etc).Having it occur from Day to Night over time with sunrise/sunset once every 15 minutes or so just so it would feel like you were in a world of its own while playing the game. Just an idea though leave your thoughts below!
No. It changes readability of the game. I'm sure you're not implying that it get very dark, but the champions abilities are created with the current lighting conditions in mind. Changing that can dramatically change a lot of things.
The league engine doesn't even have proper lighting, it just uses a pre-set "sun" position for all the environmental shadows. It would be hard to hack in a day/night cycle and it would provide no real gameplay benefits.
12:12:12 damn = =
we could add it as a new game mode where champs get different benefits at different times of the day.
We could call it the aspect of targon a 5v5 gamemode.
A player is randomly selected and becomes an aspect, 
.
depending on different times and champs the player get's powers.
The aspects are not shown on either team's maps.
I am not exactly sure about the mechanics and the map though.
I voted yes but would change it to no. There are already a lots of players who ruin games cause "I'm lagging, can't move, blah blah blah" and I feel they'll say "I like the day/night cycle so I'm keeping it enabled even though I'm lagging. Oh and I'll stay in Ranked games too"
