I believe the Achievement Diaries are missing a small yet important piece of info: Level restriction for using each XP lamp you get as a reward.

The only diaries that contains a refference for these restrictions are Ardougne Achievement Diary(only for hard and elite tasks) and Karamja Achievement Diary (all).

 

Full XP/restrictions list:

 

Varroc - Easy - 1k - Min level 30.

Varroc - Medium - 5k - Min level 40.

Varroc - Hard - 10k - Min level 50.

 

Fremennik - Easy - 5k - Min level 30.

Fremennik - Medium - 10k - Min level 40.

Fremennik - Hard - 15k - Min level 50.

 

Ardougne - Easy - 1k - Min level 25

Ardougne - Medium - 7.5k - Min level 45

Ardougne - Hard - (mentioned in guide)

Ardougne -Elite - (mentioned in guide)

 

Seers - Easy - 1k - Min level 30.

Seers - Medium - 5k - Min level 40.

Seers - Hard - 10k - Min level 50.

 

Falador- Easy - 1k - Min level 30.

Falador - Medium - 5k - Min level 40.

Falador - Hard - 10k - Min level 50.

 

Lumbridge - Beginner - 0.5k - Any

Lumbridge- Easy - 1k - Min level 30.

Lumbridge- Medium - 1.5k - Min level 35.

Thank very much for bringing this to our attention. The guides have been edited accordingly and you have been credited :thumbsup: