ModernUO/Projects/UOContent/Spells/Ninjitsu/Backstab.cs

using System;
using Server.SkillHandlers;

namespace Server.Spells.Ninjitsu
{
    public class Backstab : NinjaMove
    {
        public override int BaseMana => 30;
        public override double RequiredSkill => Core.ML ? 40.0 : 20.0;

        // You prepare to Backstab your opponent.
        public override TextDefinition AbilityMessage { get; } = 1063089;

        public override bool ValidatesDuringHit => false;

        public override double GetDamageScalar(Mobile attacker, Mobile defender)
        {
            var ninjitsu = attacker.Skills.Ninjitsu.Value;

            return 1.0 + ninjitsu / 360 + Tracking.GetStalkingBonus(attacker, defender) / 100;
        }

        public override bool Validate(Mobile from)
        {
            if (!from.Hidden || from.AllowedStealthSteps <= 0)
            {
                from.SendLocalizedMessage(1063087); // You must be in stealth mode to use this ability.
                return false;
            }

            return base.Validate(from);
        }

        public override bool OnBeforeSwing(Mobile attacker, Mobile defender)
        {
            var valid = Validate(attacker) && CheckMana(attacker, true);

            if (valid)
            {
                attacker.BeginAction<Stealth>();
                Timer.StartTimer(TimeSpan.FromSeconds(5.0), attacker.EndAction<Stealth>);
            }

            return valid;
        }

        public override void OnHit(Mobile attacker, Mobile defender, int damage)
        {
            // Validates before swing

            ClearCurrentMove(attacker);

            attacker.SendLocalizedMessage(1063090); // You quickly stab your opponent as you come out of hiding!

            defender.FixedParticles(0x37B9, 1, 5, 0x251D, 0x651, 0, EffectLayer.Waist);

            attacker.RevealingAction();

            CheckGain(attacker);
        }

        public override void OnMiss(Mobile attacker, Mobile defender)
        {
            ClearCurrentMove(attacker);

            attacker.SendLocalizedMessage(1063161); // You failed to properly use the element of surprise.

            attacker.RevealingAction();
        }
    }
}