Feel free to have any conversations out of character here. If you have questions, use the Questions for DM chat, so they don't get lost in the flood of conversation.
You're right. I sometimes forget that 5E, a game that tried to simplify and streamline most of its rules, made the idea of "holding an action" needlessly complex and unintuitive.
Yeah, I've seen it often forgotten that it requires concentration to "ready a spell", and there's no exception for cantrips. It does make some sense, though, as you can take advantage of this to ignore counterspell. If you hide behind full cover, "ready a spell" and then release it when you exit cover, you can't be counterspelled as the casting happened when you readied it, not when you released it. Costing your concentration to do that seems fair.
I would submit it makes no sense, and the "avoiding counterspell" tactic actually makes it worse, not better. Holding an action is simple and straightforward. Of course they had to fix it until it wasn't.
Granted, my feelings about a rule doesn't change that it is, in fact, the rule. It's just stupid.
Agree to disagree. I like to think of holding a spell as shaking a soda bottle and deciding when to open the lid. You give the bottle a lot more focus when it wants to burst and you don't want it to. But that's just my take.
Keep in mind I'm talking about the idea of a Readied Action in general (not just spells) versus the classic Held Action.
One is simple, one is not.
Also, even with your shaken soda example... the idea that you would have to stop someone from shaking the bottle and not stop them from opening it is rather ridiculous. Then add in that if you decide you're going to open the lid when your buddy comes in the door, but he stands outside... you can't just step outaide the door and open it instead.
Needlessly complex. One of the few 5E changes I absolutely hate.
@Ironmonger42 just want to note that I admire the job you are doing here to keep us playing within rules. And add a personal opinion that it Ready action in 5e is designed both logically and reasonably.
I want to ask you if you would prefer players tell you their PC (and summons) actual locations on battle map, i.e. Isaiah moved to T12 and summoned elemental at Q23. I were asking my players to do that for me when DMing. It saves DM time updating battle map
I don't require my players to tell me exactly where they move to, but if they don't tell me then I'm going to move them where I think makes sense, not where they may have intended. It would be best to say the exact location.
I haven't decided how tall the boat is, but seeing as it has a lower deck I will say that at the bare minimum, if you dive off the boat and want to get back on the boat to jump off again (assuming you don't stay underwater), it will take your full speed to get back on, though one could argue it would take your action too unless you had a climbing speed or magic item.
Without a climbing speed it still takes 2 feet to climb 1 foot, but any athletic check I may ask would be at advantage due to the rope. Not much of a factor now, seeing as the serpent constricted you.