The decay demotion system is applied from diamond tiers along with the grace point system.
Grace points are points that protect against demotion due to unactivity.
Diamond gets 3 grace points per game (max. 15 points).
Not playing after 15 days deducts 1 point per day.
Immortal/Titan get 3 grace point per game (max. 10 points).
1 point is deducted for each day of not playing.
League Points (LP) will be reduced depending on how long you have not played a ranked game.
It will be reduced until Platnum 1.