Luck in a dream is read as the feeling of being favoured or passed over by chance. Dream books take it as a picture of how much control you feel you have, not as a promise of anything.
Where in your waking life have you met something like this lately?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.