1. If a Pokemon faints, it is considered dead and must be released immediately.  If a full-party wipe occurs, the game continues as long as there are living Pokemon still in the PC.

2. Only the first wild Pokemon encountered in each area may be caught.  If the Pokemon dies or runs away, you can't try again.  If the first encounter is a Pokemon already captured (including evolutions), it cannot be captured and a new attempt can be made.

3. Items can only be used in battle if the opponent has used one.

4. Important fights (gym leaders/team boss/elite four/etc.) can only be fought with Pokemon at or below the highest level of their Pokemon.