PHD is a passive item.
A certificate with "PHD" written on it.
Isaac wears a surgeon's mask.
Changes the effects of all negative Pills to their positive counterparts. Neutral pills, such as Bad Gas, are not affected. Restores two Heart Containers on pick up. Has a 1/150 chance to identify the pill that is currently being held every frame.
If Telepills has not yet been identified as a pill in the current run (i.e. if the player has not yet used a Telepills), PHD guarantees that Telepills cannot show up in the current run.
PHD has the potential to be a very powerful starting item, as it turns most pills into permanent stat increases.
- PHD is an abbreviation for 'Philosophiae Doctor' (Latin for 'Doctor of Philosophy').