Arcane Wager Arm

This prosthetic appendage was developed by a particular tinkerer with eye for chaos. To attune to this item, you must use an action to attach it to your arm at the shoulder, at which point it immediately attunes, and magically syncs to the user.

While attached, the prosthetic provides these benefits:

• The prosthetic is a fully capable part of your body.
• You can take an action to remove the prosthetic, and it removes itself if your attunement to it ends. It can’t be removed against your will.
• The prosthetic is a magic melee weapon with which you’re proficient. You may also make unarmed strikes with it. It deals 1d8 Force damage (your Strength modifier applies to the attack and damage rolls, unless you are able to substitute another modifier in place of strength for melee attacks, in which case you may use that modifier instead)
• Once per turn, you may use a bonus action to charge the Arm’s slot machine handle, priming a special attack. The effects and properties of this attack are determined by rolling 1d6 on each of the three tables below to determine the Power, Form, and Damage type of the attack.*** This attack remains available to you until you complete a long rest, charge the arm again, changing the available attack, or score a critical hit on an attack made with this arm, as scoring a critical hit automatically charges the arm without expending a bonus action.
• You may charge the arm’s special attacks a number of times per short rest equal to your wisdom modifier. Players with proficiency in Arcana may add their proficiency bonus to this number, if your DM allows. Attempting to charge the arm with all charges expended results in an immediate 1, 1, 1, outcome. (See “*” below) 

* When an attack is centered on the attacker, the attacker is considered immune to the effects of the attack for as long as they persist, unless the attacker rolls 1, 1, 1, in which case the special attack goes off immediately, affects the user, and does 6d8 damage instead of 1d8. Should this happen, the arm is considered broken until a short rest is taken to repair it, and a DC20 Arcana check is succeeded while doing so. Proficiency with Tinker’s Tools can be used to gain Advantage for this check, and Proficiency with Thieves Tools can be used to substitute a sleight of hand check at the same DC.

** When 6, 6, 6, is rolled, this attack roll automatically hits, and is considered a Critical Hit, meaning that damage dice are already doubled, so while a 6, 6, 4, attack would result in 12d8 psychic damage, a 6, 6, 6, attack does 24d8 piercing damage to creatures immune to piercing damage, and double that to creature not immune to piercing damage.

*** For DMs seeking to limit a player who receives this item early in a campaign from being able to abuse it, you may choose to consider the play non-proficient with the item, and may further limit its use (recommended for players under level 10) by having your player use D4s instead of D6s to determine special attacks, thereby limiting the higher end functions of the item, and increasing the chance of critical malfunction.

Notes: creature missing an arm, Healing, Damage, Control, Combat