Multiplier Decay
From WikiRaider
The Multiplier Decay decreases the Multiplier in Lara Croft: Relic Run until it reaches the base multiplier.
While the multiplier increases each time Lara collects an item (Coins, Powerups, Clues) or hits a target in a combat sequence (Health Crates, Coin Crates, Enemies), it automatically decreases after a certain amount of time has elapsed without any items collected or targets hit. The higher the multiplier the faster it decays.
The Multiplier Decay can be stopped while using vehicles like the ATV by wearing the Biker Outfit.