In fantasy settings with sufficient magic, there is likely to be a low level spell to send a simple message from person to person. Consider that a permanent magic item with this power is essentially a one way cell phone. This is such an indispensable item that no one who could afford it would be without one. Most mid level adventurers, wealthy NPCs and government offices would all have one. The watch might have a handful so active patrols could requisition one to call in reports, update movement, and request backup. Merchant caravans are likely to do the same. Similarly, adventuring parties could spring for an extra device and leave it in town with a henchman who is responsible for mapping, keeping tabs on where everyone is, and sending in mercenaries when things go pear shaped.
But wait, there’s more! Let’s looks at economics: manufacture of magic items is often expensive but costs can usually be reduced with the right combination of rare items. With these devices being so in demand, it makes perfect sense that industries would spring up around farming these materials to drive down the cost of manufacture. This might reduce the price to the point that even lower level adventurers, smaller businesses, and minor government officials might have one.
And where there’s a booming industry there’s going to be innovation. Soon you’re going to see all kinds of variants: tablet versions that you write on to send written messages and that heat up when you receive a message; perfect for the rogue who doesn’t want their position compromised when someone calls them unexpectedly, versions you can see through so the mage can memorize spells with his spell book safely at home with his apprentice, versions that scan surroundings and automatically note dimensions of rooms for mapping, etc. All these niche versions will be pricey. There’s unique spell research put into them and there are no ready sources of special materials they require, but the professional adventurer will be willing to shell out the extra gold both for the additional functionality and for the prestige of owning bleeding-edge magic.
Of course don’t overlook the specialty wizard build that’s constantly researching new functions and tinkering with the team’s devices. They’re not only enhancing the team’s functionality, they’re also a constant springboard for adventures: “Sure I can upgrade your crystal to do that, but I’m going to need the heart of a fire elemental and some pristine obsidian.” Whether they’re an NPC or a PC, they’re going to be a welcome addition to any group.
But this is just the beginning. How long before this technology is leveraged into full blown computers? After that comes a fantasy internet. Adventurers can quickly run a magisearch for “tips for fighting medusas” and get advice from other veterans (and from armchair know-it-alls, so be careful what you read). This opens a whole new realm for adventure and campaigns. Helping expand the magenet, researching new information for upload, testing new technology. You can even run a campaign where PCs are part of a resistance fighting an oppressive state that censors the magenet. Sure, this seems a lot like turning your game into a fantasy…er Shadowrun, and it is, but it’s an interesting twist to the assumptions of fantasy RPGs for a game or two.
Of course the dwarves have a completely different system (vibrations through stone made and picked up by small earth elementals imbued into devices), as do the elves (massive storage in living trees, distributed by interconnected plant life force). Plenty of other minor nets exist as well. There’s even segments of an ancient net of some sort running through the astral plane. The teams charged with interfacing these systems maintain bizarre hodgepodge sub-systems just to get them barely communicating (a mud elemental rigged into the dwarven network with plants tied into the elven network planted in his body for example) and constantly need some oddball component or another to keep the entire thing from crashing down around their ears.
How would a fantasy internet enhance a campaign? What challenges would it bring? What does a goblin internet look like? Does this go the whole way to Mechanus?