Realmgates are the ancient magical portals that connect the Mortal Realms to one another, making travel between the planes possible without crossing the deadly gulfs that separate them. They take countless forms: carved archways, standing stones, waterfalls, cave mouths, whirlpools of quicksilver, or rings of fire, each one a doorway that steps travellers across unimaginable distances in a single stride.
Because the realms are so vast, whoever controls a realmgate controls the flow of armies, trade, and refugees across entire worlds. This makes them the most fiercely contested places in the setting. During the Age of Chaos, the Dark Gods' legions seized or corrupted gate after gate, twisting some into daemon-haunted passages, and when Sigmar launched his counter-invasion the opening campaigns became known as the Realmgate Wars for precisely this reason.
The greatest portals of all are the Allgates, colossal junctions of tremendous strategic power whose possession can decide the fate of whole realms. Lesser gates number in the thousands, some famous and heavily fortified, others lost, buried, or forgotten in the wilderness. Many function only under particular conditions, opening at certain seasons or answering only to certain rites, and unstable or damaged gates can scatter travellers to unknown destinations, or to nowhere at all.