"Verily" is a mechanic used in some New Zealand theatre-style larps to handle magical effects without breaking immersion. A genre-appropriate keyword is chosen. Statements prefixed by this keyword are not heard by the characters, but must be accepted and acted upon. Commands prefixed by the keyword must be followed. For example, the statements "verily, I appear to be Arthur," "verily, your weapons pass right through me", "verily, you may not approach", and "verily, you are struck blind" have the obvious effects. When combined with a simple rule on how long such effects last by default (e.g. five minutes), it allows for a very powerful and flexible magic system with a minimal rules load on the players. Another advantage is that information about superantural powers can be restricted only to those who know them.
Different keywords can be used to represent different types of powers within the same game.
The mechanic was first used in The Black Hart of Camelot, which used the keyword "verily". It has since been reused in Betrothals and Betrayals (using the keyword "Glamour") and in a live-combat hack of The Moorstepper on Lloegyr.