Though this topic has been covered several times, I thought that I would write up a Pin worthy explanation along with a big picture to help. Teleport is one of the most misread and misinterpreted spells that I see in the game. I am constantly being asked online (OCTGN) to help explain. I have gotten better at explaining, but still get the rage quit more often than I would like.
So here we go! Once Teleport is revealed, the two properties of most interest here is the Range and Target items. The Range property is obvious, or so you would think! The second property is Target, and is the source of most the confusion. We have two targets, Creature and Zone. For both of these targets, the Range is calculated from the Mage (or Creature) casting the Teleport spell. Above we have the Holy Light of a Priestess casting the Teleport spell on to the Darkness of a Warlock. The green arrow represents the first target in the Target Bar the "Creature” i.e. the Warlock. The Warlock must be within two zones of the mage casting the spell, in this example the Priestess, and also be in Line of Sight (LoS) to be a legal target for this spell. Now for the second Target: the “Zone”. The target “Zone” must be within two zones of the
spell caster and the zone must be in Line of Sight (LoS) of the spell caster to be a legal target. I have placed face down cards to represent legal target zones for the Priestess in this scenario. As you can see the furthest you can move the Warlock is four zones for a cost of twelve mana.
A couple of points for new players. If you have a hidden Nullify on a target of the Teleport, make sure to have the target zone identified before revealing the Nullify. LoS plays a very important part of this spell. If there was a wall with the LoS Blocked trait between the Priestess and the zone below her, the zone below her would no longer be a legal target for the "Zone" part of the spell. However, if there was a wall that blocked LoS below the Warlock, the Warlock and all zones pictured would still be legal targets for this spell, as it is the LoS of the spell caster that matters. With the upcoming release of Forged in Fire the new spell Rolling Fog, which places the Obscure trait on all zones for three rounds would completely prevent this play.
I hope this helps everyone with a better understanding of this spell and how it functions!