What would be the effects of changing the duration of a round from 6 seconds to 5 seconds?

I’m introducing the following house rule:

A round lasts 5 seconds.

What would be the effects of such a house rule? Would there be any? Would this break the game?

Out of the top of my head, I cannot think of any actions/spells/mechanics that rely on the duration of a round.


Disclaimer: The original question was a bit broader and was closed twice as opinion-based/off-topic.

How many rounds does a spell with a duration of 1 minute last?

If a concentration spell lasts for one minute (60 seconds, 10 rounds), when does one start counting down how much time it has left? Does the round you cast it in count towards how long it stays active?

First example, what if I use Aura of Vitality, which uses an action to cast then a bonus action can be taken to heal a target? The spell lasts for 1 minute, or 10 rounds. So on the turn I cast it I can use a bonus action to immediately use it, then do I get 9 more rounds or 10 more?

What about spells like Moonbeam, which don’t take effect on your turn? Moonbeam activates when a creature enters it or starts its turn there. If you’re first to go in a round then you’ll get 10 uses out of it, but if you’re last does that mean you only now get 9 uses out of it since it acts during an opponents turn?

Is there a difference between “one round” and “until the end of your turn” in terms of duration?

I’m mainly concerned about the effects that last “one round” and “until the end of turn” (like Stone Bones ToB p.84 and Inferno Blade ToB p. 54, respectively). My guess is that “until end of turn” effects end after you’ve taken your “standard” actions (one swift action, one move action, one standard action, or whatever the duration equivalent would be, like a full-round action), so the reactions you take on that round are not affected by that effect. On the contrary “one round” effects would be in effect until it’s that PC’s turn again.

However, my DM insists that both effects would last until that PC’s turn comes again, having no distinction, even if it has different wording. So, really, what’s a round and what’s a turn in this case? Are they the same?

Are the instructions given in the “Planar Binding” spell part of the casting time, or can instructions be amended during the spell duration?

The Planar Binding spell is a 5th level abjuration with verbal, somatic and material components and a casting time of 1 hour that allows the target a Charisma saving throw. If the target fails the save, it “must follow your instructions to the best of its ability”.

Are the instructions specified as part of casting the spell? Or are the instructions given after the spell has finished casting? Can instructions be updated/amended throughout the duration of the spell, or is there a one-time period during which the instructions must be fully specified?

Although the duration for the 5th level version of this spell is 24 hours, the duration increases as higher spell slots are used, lasting a year plus a day when a 9th level spell slot is used. I mention this because the longer the spell lasts, the more important the answer to this question becomes.

Woocommerce Booking – Display selected block amount or duration

I am using Woocommerce Booking plugin and I would like to display the number of blocks a user is about to book.

eg:

  • Create bookable product with 30 minute blocks, min:1, max;4
  • User selects start:9:00, end:10:30
  • Front end displays calculated price and “3 Blocks”

Is this possible? and how would I go about doing this? Is there a hook or is it a template change?

Do you get the extra attack from a Haste spell you cast on yourself with 1 round duration?

A rogue PC in my campaign has just picked up the Trapsmith prestige class and gained spellcasting this way. He picked Haste as one of his first spells. Now I wonder: His current caster level is 1. If he casts haste, how long does it last? Only the round he casts the spell? Then he would only benefit from increased speed (+30 feet or double, whichever is lower) and +1 dodge to Reflex and AC until his next turn. Or could he transfer the benefit to the next round, if he takes his move action first and then casts the spell with the standard action?

If I cast True Polymorph on my simulacrum and concentrate for the full duration, will casting Simulacrum again still destroy it?

Simulacrum states:

If you cast this spell again, any currently active duplicates you created with this spell are instantly destroyed.

Does this mean that if I take my simulacrum and permanently transform it using true polymorph into, say, a dragon, that if I cast simulacrum again, it would still instantly destroy that dragon I just produced?

If you cast a spell with a focus component and a long duration, does it end if the focus component goes missing?

I can’t seem to find a good example outside of 3rd party materials right now and pending GM or Dev input I figured I’d ask here. The example I’m specifically looking at is a spell with a 24 hour duration that uses a focus component that is an armlet worth at least 25g. If that armlet were removed for some reason (stolen, confiscated, handed to someone else, etc) would the spell duration end at that point or is the focus component only needed for the initial casting? If it were a Concentration spell I could see it needing to stick around, but IDK otherwise. Anyone have any official rulings on this?