Accuracy formulae

    /**
     * Calculates the chance to hit out of 1.0
     * @param opponent The entity being attacked.
     * @return The chance to hit.
     */
    public double chanceToHit(Entity opponent) {
        /*
         * Calculate the entity's base attack value.
         */
        int attackBonus = entity.getCombat().getBonus(entity.getCombat().getAttackType().getAttackBonus());

        if (attackBonus < 1) {
            attackBonus = 1;
        }

        int attackLevel = entity.getSkills().getLevel(Skills.ATTACK);

        switch (entity.getCombat().getAttackStyle()) {
        case ACCURATE:
            attackLevel += 3;
            break;
        case CONTROLLED:
            attackLevel += 1;
            break;
        default:
            break;
        }

        double attackCalculation = attackBonus * attackLevel;

        /*
         * Calculate the opponent's base defence value.
         */
        int defenceBonus = opponent.getCombat().getBonus(entity.getCombat().getAttackType().getDefenceBonus());

        if (defenceBonus < 1) {
            defenceBonus = 1;
        }

        int defenceLevel = opponent.getSkills().getLevel(Skills.DEFENCE);

        switch (opponent.getCombat().getAttackStyle()) {
        case DEFENSIVE:
            defenceLevel += 3;
            break;
        case CONTROLLED:
            defenceLevel += 1;
            break;
        default:
            break;
        }

        double defenceCalculation = defenceBonus * defenceLevel;

        final double MAGIC_NUMBER = 133;

        double chanceToHit = MAGIC_NUMBER * (attackCalculation / defenceCalculation);

        if (chanceToHit > 1.0) {
            chanceToHit = 1.0;
        }

        // TODO: prayer modifiers, verac effect

        return chanceToHit;
    }