Gate, Spelljammer, and the Rule of Cool

You could just say that for this casting of gate ypu use an alternate method that maybe has the portal form but only briefly, and instead of being stable it pulls everyone through at once and then disappears. The difference being that this method works better for boarding moving objects but as a result of its suddenness drops you a bit haphazardly wherever you were targeting (not necessarily in the formation or orientation you wouldve wanted). Maybe everyone gets pulled in and thrown out in a room on the ship and just kind of land on things. Or you could do the teleportation area one, i think that ones pretty cool. Makes for a nice entrance although less comical.

Depending on how you would rule Immovable Rods work (I say relative to the planet, not in total spacial coordinates), I believe spelljammer logic for how the “air-bubbles” exist would make it so things that are “stationary” or “immovable” is relative to the nearest/largest thing.

So you could allow the Gate spell to dump everyone into the same area and move with the Spelljammer ship.

I assume you’re specifically allowing same-plane access for the Gate spell for a doorway, but not the “summoning a creature” option. Otherwise the Party could conjure their enemies one at a time at their leisure.

If you want a lower spell level option, there is a level 6 spell called Arcane Gate which is effectively what they’re trying to do (range limit is 500^(ft), but upcasting to a 9^th level spell for extra range would be a reasonable houserule), same issue with being “stationary” though.

I like the idea of the Party having to line up so the Gate “hits them” as it stays stationary is space and they continue moving.

Ending up in slightly different rooms and having to meet up is also novel. I suppose you could try to figure out a logical map, but I’d just pick funny rooms like the fridge, the vault, someone’s personal quarters, and in a closet with an alcoholic still going.