When I was in graduate school, whenever I met someone who studied Old Norse, I’d ask if they knew anything about skating in the literature. Usually, after a few minutes’ thought, the answer was, “there’s the hockey game in Gísla saga…”.
The hockey game is knattleikr, a ball game that was usually (but not always) played on ice. I keep hearing vague rumors about people thinking players used bone skates, but I haven’t found any concrete references supporting it. I’m glad nobody really thinks that, because it’s not true. Bone skates did not allow the agility necessary for a violent ball game. It is extremely difficult to stop and turn on them. Imagine playing hockey without being able to stop or turn!
That’s not to say knattleikr was anything like hockey. The sagas are pretty vague about the rules, but it clearly involved one or more balls and a stick (knatttré) for each player or pair of players. The stick may have ended in a basket, like a lacrosse stick. The practice of pairing players of approximately equal strength, which is occasionally mentioned in the sagas, is paralleled in historical lacrosse.
Knattleikr probably did not take advantage of the slipperiness of ice. The game required a large, open area to play in that provided space for spectators. A field would have worked as well, and probably did in the summer game described in Gísla saga and the fall games in Hallfreðar saga and Eyrbyggja saga as well as the game played “on land” in Blómstrvalla saga. Playing on slippery ice may have added a new dimension to the game by requiring the players to be more agile, but it was clearly not necessary: knattleikr was not an ice-based game.
For more details and full references, read my paper about knattleikr in Scandinavaian Studies.