Probably been suggested before, but this will be an specified suggestion about it. Pretty much everyone knows what an ironman is or have an account for that.
An ironman is an account that does not receive help from anyone else, and has to do everything himself (with the exception of some multiplayer minigames). You will need to set your ironman status on Tutorial island, and this mode cannot be reverted!
Ironman accounts will receive a specific item (and maybe a symbol next to their name) to be able to display their status to other players.
This mode poses a new challenge to players that know the game throughoutly and strive to gain a significant spot of honour in the highscores for ironman. This would be a seperate highscore tab specifically for ironmen that shows the total level and total xp of all ironman players. Their individual stat levels are shown as normal in the rest of the highscores.
The rules:
An ironman account can not trade with other players (this also includes member rings: if you need membership on your ironman account you will need to donate for donator points);
An ironman account can not see the monster loot of other players;
An ironman account can not see the drops of other players;
An ironman account can not receive aid from other players (the aid on button is disabled), such as tele-other, vengeance-other and cure other;
An ironman account can not receive combat buffs from released butterflies by other players;
An ironman account can not participate in PvP situations where he might gain loot or experience by killing another player;
An ironman account can not participate in the duel arena;
An ironman account can not obtain loot from the Falador Party room;
An ironman account can not buy player items from stores such as the General store, he is only allowed to buy items that are normally in stock;
An ironman account can not buy a guardian angel.
An ironman account will not receive slayer experience from killing a monster if anyone else tagged it with damage (so not just more than 50% damage);
An ironman account will not receive items from admin-hosted events (as game and high administrators may trade through all trade restrictions).
An ironman account will lose all his items upon death;
Allowed:
An ironman account is allowed to participate in minigames such as Castle wars and Pest control, but does not gain combat experience playing it. He can however, gain rewards from it;
An ironman account is allowed to combat bosses or whatever monsters in a group, but will be unable to share his loot, or others to share loot with him;
An ironman account is allowed to use the rope down to the kalphite lair if applied by another player;
There's also been an ultimate ironman mode around that once you DIE ingame, outside a safe death zone (minigames, etc) your death will be PERMANENT. The challenge is to see who would come furthest. The rules would be the same for the rest, but you are not allowed to buy a Guardian angel for your ultimate Ironman account. I think this would also be cool to add, but that means we need another new highscores tab for this type of ironman. Also, this mode might be prone to griefing, as a hacker or anyone else quickly able to access your account could grief it by dying, disabling your account permanently.
Feedback on the rules please, and check for loopholes!