NWScript:

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//:: Summon Creature From Item
//:: SUM_MOB_FROM_ITEM
//:: Copyright (c) 2002
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/*
    Summons a creature after using the summoning
    amulet.  The summoning lasts for 10 turns.
*/
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//:: Created By:  Eoweth (eoweth@cox.net)
//:: Created On:  June 22, 2002
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/*
    Called from onActivateItem under Module Properties
*/
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void main()
{
    // Declare major variables
    object oMaster = GetItemActivator();
    // Replace "CREATURERESREF" with the sCreatureResref of whichever monster you wish to summon.
    // Note that sCreatureResref is *not* the same as it's Tag.
    //  You can also replace the _3 with 1-3 for different summon effects.
    effect eSummon = EffectSummonCreature ("CREATURERESREF", VFX_FNF_SUMMON_MONSTER_3 );
    // Apply the VFX impact and summon effect
    // Adjust the TurnsToSections(10) to reflect how long you want it to last.
    // You can use HoursToSeconds(), RoundsToSeconds() or TurnsToSeconds().
    ApplyEffectToObject (DURATION_TYPE_TEMPORARY, eSummon, oMaster, TurnsToSeconds(10));
}