2009Scape Official Forums

Basically either a toggle (which is preferable as not everyone would want this) or just straight up changing all quests to give 1x rates on combat xp regardless of mode/XP rate chosen. Reason being ability to create classic/unique account builds without having to play 1x mode. Examples: Zerker build is basically impossible on 5x due to Dragon Slayer and Fremennik Trials bringing your defence level straight to 50. It also future-proofs for any quests that come out in the future related to unique builds around combat XP and defence/attack levels, although accounts that already have certain levels would probably have to start again.

I agree with summer, if the goal here is to build a unique account, then going 1x makes even more sense because it makes your account more prestigious.

You chose to play on a boosted XP rate, the consequences for your decision are your own.

1x has 1x quest xp.

No sense in ruining 5x players' quests and making it unfair to future players that didn't get to indulge in boosted xp that current/past players received upon completion of said quest(s).