in pvp if there are many people attacking you, you are meant to receive an Antigank Cr bonus. The bonus is 1 CR for every player above 1 that is attacking.
In the wurm unlimited code this appears in Combathandler.java in the method getCombatRating.
if (this.creature.isPlayer())
{
int antiGankBonus = Math.max(0, this.creature.getAttackers() - 1);
combatRating += antiGankBonus;
this.creature.sendToLoggers("Adding " + antiGankBonus + " to combat rating due to attackers.");
}
Around the time of the recent priest overhaul or possibly just before that, it seems this bonus is no longer working.