Just prowess without stacking. I mean it does still stack with Prowess, itself. But whatever.

This does stack, though?

Is it meant to say "This gets +1/+1 if you've cast a noncreature spell this turn?"

Did you have a reason behind creating this mechanic?

It's prowess but now it doesn't use the stack? Is that what you mean?

Yeah, but Link was right, my wording was wrong the first time. Also multiple instances don't stack. So you could like put it on an aura with less confusion. And there's less to track because when the different creatures enter the battlefield won't cause them to get different boosts. Also, you could like throw Finesse on an instant as a combat trick.

Not sure how this fails to stack? A second instance of finesse would be giving a second set of boosts?

I'm not really sure how to make it unstackable really. Maybe rely on horrible comprules sorting it out and the reminder text being something like "This creature has +1/+1 ONLY" ?

Lifelink isn't stackeable. Reminder text isn't rules text. The actual game rules would have to specifiy whether multiple instances stack.

Lifelink doesn't stack because it's a replacement effect. This is a triggered ability.

Well it’s now actually a static ability. I think I might put this in my velocity set as a +1/+0

It's a static ability, but it is cumulative. The rules explicitly state for each keyword ability whether multiple instances are redundant or cumulative, but they never contradict the ability as worded in the reminder text. This is valid the same way reminder text is certain to never incorrectly use or omit signal-words/-characters (which is how we know this isn't a triggered ability as the rules would not contradict the reminder text in lacking a signal "when", "whenever", "at" etc.)

For the same reason I could tell you that lifelink indeed is not defining a replacement effect. It's a static ability altering the result of dealing damage.

"Reminder text isn't rules text" means you can shortcut certain phrases and roll up multiple clauses into one, but reminder text still follows certain conventions that allow a savvy player to correctly determine certain aspects e. g. the type of abilities used (suspend and morph reminder texts don't feature a colon? These mana payments must represent special actions rather than activated abilities and don't use the stack.) and also whether the effect of each instance works separately or multiples are redundant.

All the other benefits are correct and welcome though, which is why I would have done prowess/finesse like this (or actually as suggested by link) in the first place i I planned to make it evergreen.

The correct wording for the reminder text is hard to find, but would probably be something like

> A creature with finesse gets +1/+1 for each noncreature spell its controller has cast this turn.

That way it is more of a reminder text for the keyword ability than a reminder text about the effect this specific instance of the keyword ability has. Now as multiple instances of finesse don't whether a creature is a "creature with finesse" that characteristic by definition is redundant - even a creature with multiple instances of exalted would only be affected once by a rule/card affecting each "creature with exalted".

The rules would have to be written accordingly and the reminder text tested and probably adjusted even more since the new reading introduces another ambiguity.