Encounter Number
From Talisman Wiki
Adventure Cards must be dealt with in the order determined by their encounter number (the number at the bottom right corner of the card).
The lowest number is tackled first, then the next lowest, and so on. In the case of a tie, the character encounters Adventure Cards in the order they were drawn.
One exception to the rule about resolving Adventure Cards in encounter number order is that Adventure Cards with instructions that result in their being placed in a space other than the one where they were drawn are dealt with first, before any other Adventure Cards are resolved. If placed elsewhere, an Adventure Card does not affect the character who drew it at that time.