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: 
### "Electrical magic"-based teleportation: requires a conductive path.

Suppose your teleportation magic makes your teleporting person act as a self-propelled surge of electrons. As long as they are in physical contact with a conductive surface or conduit, they can teleport to any other point on it with enough space for them to materialize at the other side.

This would impose pretty strong limitations on general use.

* Most dirt/rock/concrete and other surfaces one could stand on would not be immediately usable.
* Bodies of water and wet surfaces (eg. during/after rain) would be easily traversable.
* In urban settings, perhaps a likely use would be teleporting around the electrical grid between points of exposed wiring.
* To use it in non-conducting settings, the teleporter would probably carry coils of wire with throwable weights or a grapnel gun, or perhaps something that splashes water, to deploy in the field.

If you want to impose limitations based on frequency, you can consider heat generated by the teleporter's passage through the medium. If they teleport across a thin film of water on pavement, perhaps the heat of their passage would evaporate too much water for them to take the same path back. If they teleport through a normal circuit in a suburban home, perhaps they'd set off the breaker and not be able to go back through that line.

Related to this, you could add a limitation that they must know, ahead of time, where they are going to rematerialize. Perhaps in electron-surge form, they cannot perceive the world outside of their conductive conduit--at risk of death or severe injury, they must be certain they are re-materializing in a place with sufficient room for their body.
Please be much more imaginative. Either explain or drop any difference between “using magic” and how else they might "teleport”.

Explain how a “hand” matters, rather than a foot or shoulder, knee or elbow.

A “circular arena…” is one thing. A “circular area…”; even “a circle…” very different. You might not care.

Your “floating” might have a use, or not.

If it is written that limitations should be set to avoid anything being too powerful, you might be able to Post where or when.

To disregard earth magic/manipulation when your Question is solely about “contact-based teleportation”, as explained by you as being in contact with the earth, seems like a contradiction in terms.

Limit what you want to 75-100m, usable only every second or two and with wind magic mainly.

Specify whether you’re writing about one second or two.

Name anyone who in a crisis, didn’t see all the difference in the world between one second and two.