Do ball bearings require more than 1 save when moving across the tiles?

Ball bearings cover a square area that is 10 feet on a side. A creature moving across the covered area must succeed on a DC 10 Dexterity saving throw or fall prone. But is this for every square they move across?

And if it is once per ball bearings, what happens if they enter a 2nd patch of ball bearings that is connected to the 1st?

Crystal ball and scrying

The Scrying spell has as its material component

A focus worth at least 1,000 gp, such as a crystal ball, a silver mirror, or a font filled with holy water

The magic item crystal ball says

While touching it, you can cast the Scrying spell (save DC 17) with it.

If using the magic crystal ball to cast scrying, you would not need to use the crystal ball itself as the focus and material component for the spell it allows you to cast, per DMG p. 141:

Some magic items allow the user to cast a spell from the item. The spell is cast at the lowest possible spell level, doesn’t expend any of the user’s spell slots, and requires no components, unless the item’s description says otherwise.

But suppose you actually knew the spell and could cast it yourself. If you did not have a silver mirror or holy water font, could you use a non-magic crystal ball as a material component?

That is, is the spell specifically asking for the magic item crystal ball, or is a non-magic ball of crystal, provided it is worth 1000gp, sufficient?

For reference, on the PHB adventuring gear list, an arcane focus "crystal" is worth 10gp, while an orb (with the same weight of the magic item crystal ball) is worth 20gp.

Can a Fireball, a fragile glass jar, and a lot of ball bearings make a “Claymore”-like explosive device?

My rogue has some ball bearings and of course, he wants to build Claymores. He talked to me about it beforehand since he was excited. I would like to see if he can make this work, but I told him lamp oil and the like doesn’t explode, but by all means, throw that pouch of lamp oil and ball bearings lit into a room and watch… slow burning ball bearings.

He has been thinking about it more and found oil of impact as an option but that is cost prohibitive for him ATM, but also he asked an interesting question: could the wizard cast a fireball into a breakable glass jar? (He got the idea from the Mad Manor of Astabar and the glass sphere in the wizard’s bedroom.) I looked around but couldn’t find any resources as to whether that is allowed.

Can he make that work?

The rogue and wizard in the party are level 5.

For Ring of Shooting Stars, can Ball Lightning affect a creature when you move it into their space?

The Ring of Shooting Stars has the following feature (emphasis mine):

Ball Lightning.

You can expend 2 charges as an action to create one to four 3-foot-diameter spheres of lightning. The more spheres you create, the less powerful each sphere is individually.

Each sphere appears in an unoccupied space you can see within 120 feet of you. The spheres last as long as you concentrate (as if concentrating on a spell), up to 1 minute. Each sphere sheds dim light in a 30-foot radius.

As a bonus action, you can move each sphere up to 30 feet, but no farther than 120 feet away from you. When a creature other than you comes within 5 feet of a sphere, the sphere discharges lightning at that creature and disappears. That creature must make a DC 15 Dexterity saving throw. On a failed save, the creature takes lightning damage based on the number of spheres you created. (4 spheres = 2d4, 3 spheres = 2d6, 2 spheres = 5d4, 1 sphere = 4d12)

Does this mean that the sphere discharges lightning whether you move it within 5 feet of a creature or whether a creature moves within 5 feet of it?

What happens if you move it within 5 feet of multiple creatures at once (or multiple creatures move within 5 feet of it at once)?

Catching ball – finding the maximum number of caught balls

I’m attempting to solve the following problem:

Balls are falling from the sky. We know at which location (on a straight line) will each ball drop, and we know the time (in seconds) at which will the ball reach the ground. We are trying to catch them into a ball net, which we can move left or right, but each movement costs 1 second. The initial position of a ballnet is always on the left (position 0). We are allowed to > drop (not catch) $ k$ number of balls.

What is the highest score we can achieve?

My first attempt at solving this was a greedy algorithm:

if the |next ball position - current position of the ball net| > (time of the next ball - current time)       then attempts++      if attempts>$  k$              print game over else      current ball net position = next ball position      current time = time of the next ball      score++ 

however my algorithm doesn’t take into consideration that sometimes it’s better to sacrifice some number of balls in order to reach a higher score in the long run. This needs an approach via dynamic programming, I think.

Is this problem a known one so I can find some help? Could you help me with this problem? I can solve this in a greedy way, however I am failing to do it dynamically.


Creating custom magic item: Teleporting Tea Ball

I am playing a silly little old lady Druid in my upcoming campaign (D&D 3.5). I want her to specialize in poisons. My DM has let me create a list of minor poisons herbs that I can use.

What I want is to create a teleporting tea ball. This will on command teleport into the stomach of my attacker with the poisonous herb. This then poisons the foe. Then with use of command word the tea ball is teleported back to my character (continuous use). Not the most effective way to damage a foe but I thought it would be funny.

If I’m doing my calculations right to make this wondrous item it would cost 88,200 gp.

(teleport object 7th lvl spell x caster lvl 7 x 1800)

Does this seem a fair price?

Do the ball lightning and spark shower functions of a Ring of Shooting Stars allow saving throws?

In the SRD it states:

The first special function, ball lightning, releases one to four balls of lightning (ring wearer’s choice). These glowing globes resemble dancing lights, and the ring wearer controls them in the same fashion (see the dancing lights spell description). The spheres have a 120-foot range and a duration of 4 rounds. They can be moved at 120 feet per round. Each sphere is about 3 feet in diameter, and any creature who comes within 5 feet of one causes its charge to dissipate, taking electricity damage in the process according to the number of balls created.

It also states:

The spark shower is a flying cloud of sizzling purple sparks that fan out from the ring for a distance of 20 feet in an arc 10 feet wide. Creatures within this area take 2d8 points of damage each if not wearing metal armor or carrying a metal weapon. Those wearing metal armor and/or carrying a metal weapon take 4d8 points of damage.

Neither of these functions directly address a need to either make a saving throw or the requirement to make a ranged attack to hit a target. Should these functions require either saving throws or attack rolls?