Question: In my story, there is a character that is capable of using magic or an ability that allows them to "teleport" as long as they are in contact with the ground or the area that they want to use it on with at least one hand.

For example, in the middle of a circular arena 100m in diameter, as long as they are touching the floor (with a hand), they can teleport anywhere as long as it is "connected" or still physically part of the arena (which means that any floating rocks won't count, and they wouldn't be able to use it to get away from the arena in the case that it is floating).

What limitations can be set on it to avoid being too powerful, and with limitations in mind (or not), what would be the best type of magic/ability to use with it? (disregarding earth magic/manipulation)

My thoughts were to limit it to 75-100m and only usable every second or two, and to be used with wind magic mainly (if mist or fog can be made using wind magic).

Answer: 
**Make her as powerful as you imagine she is.**

Because that is where the awesome is! You worry your character will be overpowered which means you can imagine her doing overpowered stuff. You worry she will be able to do stuff no-one can counter. And I think you like it. **Have her do that stuff!** Please! Have her totally thrash her opponents with her overpowered skills! That is what I want to read.

But then how to beat her? That will be more fun to figure out than how to limit her. You do not need to figure out how to limit the character you can imagine. You need to imagine other characters on her level. Figure out how her opponents can best her or at least equal her. Or team up with her? Woo! Yeah!
One of the easy ways to eliminate the more extreme abuses is a line-of-sight limitation. You can only teleport to a location if you can currently see it. That puts a hard cap on the range of the effect, and introduces opportunities for opponents to disrupt it (fight indoors, obscure their vision, etc). Teleporting somewhere you can't see isn't a really good idea anyway, because you have no idea if the laws of physics will even permit you to exist in that space (ending up inside a solid object would be game over for you).

For an extra twist, you can limit how close you arrive to your target point to be dependent on how clearly you can see that point. For example, stick out your thumb and hold it at arm's length, covering up your target. The area of your thumbnail represents the size of the area in which you might end up. When teleporting across the room, that area is only a few square inches so accuracy isn't really an issue. Teleporting to that hill far in the distance could be a problem, though. That same thumbnail-sized area is bigger than the apparent size of the hill, so you might miss your target completely and end up somewhere undesirable.

Any sort of teleportation is going to be rather overpowered in combat, simply because it lets you evade attacks nearly perfectly. The most straightforward way to reign in the usefulness would be to make teleportation not an instantaneous process. The caster has to focus/concentrate/channel for a period of time before teleporting. This prevents it from being used *reactively*, which is where most of its overpowered nature comes from. It also leaves your caster vulnerable just before they teleport, which means it has to be used much more strategically. Great for sneak attacks or initiating fights but once the fight starts, you can't fight invincibly like Nightcrawler in X-Men United.

You can even incorporate this into the lore if you want. Teleportation is a form of shadow magic. The caster channels their magic to send their shadow to a distant target location. Once the shadow reaches the destination, the caster will suddenly find themselves there as well (like how you can travel to the other room and turn on the light to make your shadow appear at *your* location, only it works the other way around). The shadow travels at a certain speed, say, 10x the speed of the caster. The caster would then have to channel for some brief minimum length of time *plus* however long it takes for the shadow to travel from A to B. That won't completely preclude its use as a combat escape mechanism, but will require your character to earn themselves enough breathing room to complete the cast.