They were in melee range (on a grid)
Think of this as a 10' hallway. If you were standing in a 10' grid of a hallway and you were on one side the spawn was on the other, then your squares are adjacent to each other.
A medium creature controls a 5x5 space. Both you and the spawn are medium. If playing on a grid, your spaces are adjacent and cover the full 10' width.
This works the same way, just vertically.
In order for you to have been out of standard 5' melee range, the hallway would have had to be 15' high in order for there to be a space between you moving the target out of range.
Likely in range for theatre of the mind
In this scenario, there is some more flexibility. But as you've provided your height and we know the general size of the Spawn, it should still have been in range. And if the Spawn was prone on the ceiling to try and squirm away (which with your arms reach above your head is questionnable at best), you may have earned advantage on the attack.
The second scenario is correct: Spell slots = resources
Once you create a cannon {using an action+tools}, you can't do so again until you finish a long rest or until you expend a spell slot of 1st level or higher
The key to this is the "again", the "until" and the "expend" - there is a resource cost for summoning a subsequent cannon after the free "first cannon of the day." The artificer either waits for a long rest to get another free cannon, or, the artificer expends a spell slot to get another cannon before that long rest recharges the free cannon. The creation of a cannon does not take two actions; - the Artificer spends a spell slot to create the next cannon(s). (If after "or higher" they had added "to create one" it would have better matched how they phrased it in the UA - Jeremy Crawford's tweet indicates that they intended it to work the same way as in UA).
The subsequent cannons resemble the Ranger "Primeval Awareness" class feature ability in that the character expends a spell slot to activate a class feature.
Primeval Awareness
Beginning at 3rd level, you can use your action and expend one Ranger spell slot to focus your awareness on the region around you. For 1 minute per level of the spell slot you expend, you can {snip}...
Sadly for the Ranger, they don't get the first use for free as the Artificer does. We now initiate a mass protest against WoTC for not loving the Ranger class
A spell slot is used to create the next* cannon(s).
Cannons last for an hour or until the cannon reaches 0 HP.
It disappears if it is reduced to 0 hit points or after 1 hour. You can dismiss it early as an action. (RftLW, p. 59)
The order of operations would play out like this:
- Create cannon (first cannon of the day). (Uses an action, no spell slot consumed)
- Other things happen. (Likely combat, or time expires ... )
- Same adventure day, you need another cannon, or, you want to change the kind of cannon you have (there are three kinds).
- Expend a spell slot to create the next one
You could run yourself out of spell slots if you go cannon-happy
A likely reason for subsequent cannons costing resources: prevent the creation of multiple cannons that cost no resources. Compare case 2 with case 1, in terms of resources:
- Case 1: 1 cannon + as many cannons as spell slots + all those spell slots cast as spells.
Case 2: 1 cannon + as many cannons as spell slots versus
Case 1 is a significant resource boost for one adventure day for 6th level Artificer, for example
Artillerist artificer's Eldritch Cannon feature says, "Once you create a cannon, you can’t do so again until you finish a long rest or until you expend a spell slot of 1st level or higher." In response to a question about whether spending a spell slot on anything else is sufficient to create a new cannon, Crawford replied: "Eldritch Cannon does let you spend a spell slot to create the cannon. That slot must be spent specifically on the cannon, not on something else." (From this tweet)
Experiential notes:
That's how we did it using the Artillerist from the final Artificer UA. This feature is roughly unchanged from that version of Artillerist.
IMO, this can be very powerful, but if the whole campaign is in Eberron, with its elevated power levels, it probably won't be that big of a deal.
The text from the last Artificer UA; this points toward some design intent.
Arcane Turret
{description} It disappears if it is reduced to 0 hit points or after 10
minutes. You can dismiss it early as an action. When you summon the
turret, you decide which type it is, choosing from the options on the
Arcane Turrets table. {more actions} . You can summon a turret
once for free and must finish a long rest before doing so again. You can also summon the turret by expending a spell slot of 1st level or higher.
1 A Protector cannon can be a lot better than cure wounds ...
You mentioned cure wounds as the spell, so I'll point out that the Protector cannon is often a better use of a level 1 spell slot than cure wounds.
Fun Protector Cheese: Set up a Protector with an action, and keep loading up your allies with 1d8+Int THP each round as a bonus action. Even if the Artificer burned a spell slot to do this, that's potentially a lot more HP than a "cure wounds" (1d8+Mod) or a healing word (1d4 +mod) cast once. With three allies, you can offer each of them 1d8+mod of damage prevention (THP) each round for the cost of a bonus action. And, if you have two fights within one hour, you keep covering them in THP to mitigate damage taken - but you didn't have to use any more spell slots. Note that the THP also applies to the cannon, which will reduce the chances that it gets reduced to 0 HP during the fight. (Until you get to higher levels)
Best Answer
Yes, a Tiny-sized Eldritch Cannon (with or without legs) can be worn or carried on the body elsewhere than in the hand.
The key to understanding this issue is to recognize that an Eldritch Cannon is explicitly an object, more specifically
rather than a creature.
As an object, the Eldritch Cannon doesn't work like a creature.
The rules on creature movement and creatures occupying spaces don't apply to objects. The rules don't expect players to engage in complex inventory-management or to supply sophisticated reasoning for carrying or navigating objects in the ordinary course. Objects, even sizable ones, can be borne about the body in any number of ways. A hat or helm might be worn atop the head, or secured by a chin-strap to dangle behind the head, or affixed to a belt, etc. A backpack or shield might be larger than one's torso, and yet they can be slung over the shoulder by a strap, or carried by a hand holding that same strap. A shield can even be strapped to a backpack. When a creature goes to pick up a backpack, we don't ask whether it's problematic that the creature is moving into the backpack's space. When the creature is carrying the backpack, we don't suppose that the backpack wouldn't naturally remain with the creature when the creature moves.
As an object, a Tiny cannon does not occupy its space. The requirement that an artillerist must
does not mean that all such cannons always occupy their spaces. The rules specify that
Absent that specification, a Small cannon would not occupy its space. So we know that if the designers wanted a Tiny cannon to occupy its space, they would have said so.
The liberal wording of the Eldritch Cannon ability offers an artificer latitude in shaping the cannon for convenience and portability.
The Eldritch Cannon ability says
That statement gives an artillerist maximally broad power to give a cannon almost any form imaginable. The only limits are the ones set out in the ability regarding size and legs-or-no-legs. An artillerist could create a cannon in the form of a hat, or a brooch, or a ham sandwich. If the chosen form is one that common sense suggests can be borne about the body, then the cannon can be borne about the body. The ability's statement that
(emphasis added) does not mean the cannon must be held in the hand. A cannon in the form of a hat could be worn on the head. A cannon in the form of a brooch could be pinned to clothing. Silly or not, it is a rules-accurate proposition that a cannon in the form of a sandwich could be clamped between the teeth. Heck, a cannon could be given a form that includes integrated straps, buckles, etc., for the very purpose of wearing it.
Finally, it is correct that a cannon with legs cannot move itself into an occupied space -- but only because the ability description says so. If the ability did not say so, there would be nothing to preclude a cannon from moving into an occupied space. By the same token, nothing prevents the artillerist from picking up a Tiny cannon and placing it on her body. Again, if the cannon were any other Tiny object, such as a glove, a key, or a lantern, we wouldn't think twice about letting a creature pick it up and wear or carry it around, moving from place to place with it. So there's no basis to say no when the Tiny object is an artillerist's cannon.