Blessing of the Solipsistic Mind

You access esoteric truths from an ancient tome by focusing deeply on your own thoughts.

• You can take an action to focus your inner mind. This focus lasts for 1 hour. While your inner mind is focused, you can’t take reactions. For the duration, when you make an Intelligence check, Wisdom check, Intelligence saving throw, or Wisdom saving throw, you can roll a (d8) and add the number rolled to the ability check or saving throw. You regain the ability to focus your inner mind when you finish a long rest.

PBtSO pg. 215