----Keep in mind that I get the certain mentality that these players are sort of "Stranded" on this, and are trying to compete to survive.----
With this scenario, you can have all sorts of fun stuff, like Have the players work with or against eachother, because they realize that the resources are limited. (If they are?)
Hahahaha, you can play all sorts of mind games with these guys! And it would be fun even to WATCH them play with eachother, seeing who allies, or teams, with who, and who fights who, and who betrays who in what way, who kills who....
And if they make teams, what kind of team do they make? One, where theres a leader, and who is top dog? Do they base it on strength? does one kill another? Oh..... how exciting! I mean, rarely does a map maker ever get to play mind games with his gamers!
So let me get this straight:
On an island there are -------
A series of people, all having different skill sets (Will these be pertaining to the island? Like, a player being very skilled with water, gets stronger near the edges of the island and strong near any sort of water, or are these spells that are just plain abilities, like attributes, like a hunter can sense when others are coming by, and can create traps and things?) [I can come up with more skill sets like this, if you need)
And these people are battling to the death: (is this on time, or do they have X amount of lives?
These people are Getting stronger: (Your question is how: Well, you could also have them all be stranded on this island, and have 2 types of Power definement : Strength and Exp. Strength will always be going down, due to constant growing of tiredness/fatigue, hunger, thirst... etc. Hunger can be satisfied through hunting the wildlife [Doesn't necessarily have to be SC critters running around.] or can be satisfied through Vegetable gathering. Now comes the challenge of EXP. This can be gained through several ways. You can select 1, or use any combo and have them all be opportunities for the players to get stronger, better, faster, harder, and all that fun stuff. In my mind, these are the possible ways.
1) Killing (A Classic. Maybe along with weak animals that you can eat from, you can have things like bears and shit running around, and if you kill it, you get some spoils, like its fur or something.)
2) Being alive (Staying alive, have a constant EXP growth from you "Learning from the island")
3) Plain old Activity in certain areas. (Basically, if you cast a spell, your mana goes down, but your EXP goes up a bit because you gain experience with casting that spell.)
4)
Selective Activity (Like #3, but instead, you have like 10 different EXP types, like 1 being for Spell casting, one being for hunting/gathering, one being plain fighting with another player... etc.)
5) Difficult Acheivments (Things like Killing a strong creature gives you EXP, though you may come into trouble finding alot of these acheivements.)
Btw, I see tons of possibilities with this map, and If you need a partner, i would love to be on-board. You can have so many things in this, its insane.
None.