MTGNexus

the ability in question:
Requisition:
You may play this spell for its requisition cost. If you do, put an equipment card from your hand onto the battlefield equipped to target creature you control as part of this spell's ability.

an example:
Pull Back, 1W
Instant (C)
Requisition 3WW
Unequipped creatures deal no combat damage this turn.

How would you word this? How would you make your own version? Which colours would you include it in? :3~

One thing I'll call out is the choice of whether to use an alternate cost (like Overload) vs an additional cost (like Kicker). Alternate costs usually imply a different functionality (do X instead of Y), while additional costs usually imply additional abilities (do X, and also do Y). For that reason, I'd lean towards using an additional cost for this.

The second thing I'll call out is that making the spell targeted has some unfortunate implications - if the target is killed, the spell fizzles. For that reason, I'd switch to use Quest for the Holy Relic wording - just put it onto the battlefield and attach it to a creature.

The third thing I'll call out is that because the hand is a hidden zone, cards that allow you to take put a card from your hand onto the battlefield usually have a 'may' clause. (your opponent may take an action in response to the spell that makes you not want to play the equipment, for example)

So, my suggestion would be:

Pull Back 1W
Instant (C)
Requisition 2W (You may pay an additional 2W as you cast this spell. If you do, you may also put an equipment from your hand onto the battlefield and attach it to a creature you control.)
Unequipped creatures deal no combat damage this turn.

Colorwise? White makes sense, since it's the primary equipment color. I'd follow with red, since it gets Magnetic Theft and a few other, similar effects. Other colors generally aren't equipment-friendly. You might be able to stretch it to blue (because of Arcanum Wings), but probably not.

Pulling back a little more broadly, I question whether you would ever have enough pieces of equipment in a set to justify this keyword being present in a limited format - it won't be relevant the majority of the time. It may work better if you expanded the mechanic to also work with auras. There are also some concerns re: free equips (ex: Colossus Hammer and Argentum Armor) that would make me be cautious with this ability.

Thanks for your thoughts! You're right about placing the equipment and attaching it being separate clauses of the same ability - that makes it more robust. The kicker model is interesting but restricts the creation of strange inverted cards, where the Requisition is cheaper than the normal cost but comes paired with a disadvantage. I'll think about all this!

Not particularly worried about single pieces of powerful equipment - they're fairly flimsy and inert once the equipped creature gets removed so in a way it's a big gamble to rely on them as a main strategy. If it was expanded to auras that'd add Eldrazi Conscription which is an even sillier card than Argentum Armor but still not quite balance threatening for the same reasons!

You should consider decoupling the attaching from the equipment put into play. If you make it two separate abilities of the same greater ability then your requisition cards gain more value by being able to equip already in play equips with bypassing a high cost or simply as an instant.