When setting the range for the round, no other effect can be used to reset the range. Skip the determine range step this round, but other pre-range effects can be played afterwards.
100925
High Ground
Maneuver, only usable to go to long range. If this minion has flight and the opposing minion does not, play before range is determined to set the range for the round to long. A minion may play only one High Ground each round.
Rulings
Once the range is set, no other effect can be used to reset the range that round, but other pre-range effects can be played afterwards. Skip the Determine Range step for that round.
If another effect was already setting that round's range (e.g. Neutral Guard), that effect has priority.