With preseason 4 about to begin, Riot Game Systems Designer Alexander "Xelnath" Brazie details the developer's new approach to vision in League of Legends, making it "both more dynamic and less taxing on single players".
On top of this is the introduction of trinkets, a new free item with a dedicated slot, so "all team members can contribute to vision control without sacrificing other areas of development".
Riot's goal for preseason 4 is to add more gameplay with vision and improving the way vision control works by diversifying responsibility. "Looking at Season 3," Xelnath explains "standard competitive support play involved buying minimal items in order to spend the majority of a player's income on wards and vision control. More gold = more wards. If a team's support was unable to fulfill that role, or fell behind their opponent, the entire team suffered."
In preseason 4, vision will cease to be an individual focus, moving to a team one. Key to this are several changes to the ward system including a personal ward limit (where old wards will be removed when players reach their limit) and the aforementioned introduction of trinkets, split into three types.
The sweeper trinket reveals and disables invisible units (and wards) but not champions. The totem trinket places a stealth ward that lasts for up to 2 minutes, dependent on level. Finally, there's the lens trinket, which reveals a portion of the map temporarily, like a "mini Clairvoyance".
Riot hopes that "these options make participating in the vision system more strategically varied for entire teams".
Check here for a full list of changes.