Progression of the Sharingan - (note this concept depends on the leveling/skill system for the game.. for this, I'm just presuming this game has a levelling system.. if not, it may work out anyway)
The Sharingan, I can gather most of the people who play this game will at one point or another be one of the Uchiha, and so here I think should be the type of progression each uchiha should have for their Sharingan.
For this concept, let's just gather that the maximum level is something like 50, or each 'skill' (e.g ninjutsu, genjutsu, taijutsu) having about 100 points, which could work out kind of like levels also.
Since it's hard to do the whole 'put under difficult circumstance' or 'emotional stress', let's do something else thats similar to the former thing that I said.
Sharingan, first tomoe - Able to be gained when you over all have 10-30 skill in your abilities, or are level 12. The way this works out is that once you are this level, there is something else that you must do to gain your sharingan, since this is going to be a pvp kind of game, I am thinking something along the lines of you must defeat X amount of players or npcs once you are at this skill level.
Sharingan, second tomoe - Able to be gained when you have overall around 50-60 skill, or are level 25 (if we're doing levels, ofcourse). You must also defeat X amount of enemy players or advanced npcs when you are this player level, or skill amount.
Sharingan, third and final tomoe - Able to be obtained once you have reached the level of around 40-45, or about 90 overall skill of your jutsu, you must ofcourse defeat X amount of players once you have reached around this player level or skill level.
(If you have any better idea's that arn't absolutely ludicrous, please share)
ABILITIES OF THE SHARINGAN.
Most of you would automatically assume that the sharingan is this super duper visual prowess of extreme opness... well, it kind of is - but I'll show you the abilities of the Sharingan just incase you just think it does some random shit that helps you see the enemies moves, or whatever.
First tomoe abilities - Increased defense, Genjutsu and dodging capabilities, decreased Chakra regeneration, and Chakra gets slowly used up. There is also a small chance of being able to unlock the jutsu that your opponent uses against you (very small with first Tomoe, due to balancing reasons)
Second tomoe - just increased of each of the above.
Third Tomoe - Increased of the first tomoe.
Players that don't have the sharingan shouldn't be able to see the amount of chakra their opponent has, so they will have no idea how long they will last, or how many Jutsu they can do before loosing all of their juice. With the sharingan, the players will be able to see the amount of chakra one has, (unless you have the Byakugan, or are highly skilled Shinobi / are a sensory kind of ninja) and will be able to easily detect if one is under a Genjutsu.
The reason for the increased defense and dodging capabilities is rather simple, the Sharingan enables you to see the movement of the enemy, which of course allows you handle situations better.
Obviously the Sharingan within the game will probably not be exactly like the sharingan from the anime, because doing that would be almost impossible, so you'd have to change it slightly.
