Playtest cards aren’t legal for play in any tournament format other than Mystery Booster Limited formats. On the other hand, we expect they will spice up a wide variety of non-tournament games (as long as everyone’s on the same page about using them!).
If another permanent becomes a copy of a leveler, all of the leveler’s printed abilities—including those represented by level symbols—are copied. The current characteristics of the leveler, and the number of level counters on it, are not. The abilities of the copy will be determined based on how many level counters are on the copy.
A permanent’s level is based on how many level counters it has on it, not how many times its level up ability has been activated or has resolved. If a leveler gets level counters due to some other effect (such as Phyrexian Seedling’s proliferatelink ability) or loses level counters for some reason (such as Vampire Hexmage’s ability), its level is changed accordingly.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Kevin Dubell
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
The abilities a leveler grants to itself don’t overwrite any other abilities it may have. In particular, they don’t overwrite the permanent’s level up ability; it always has that.
For many playtest cards, you’ll need to make a generous assumption that basic game rules would be updated to allow them to work. The Mystery Booster 2 Playtest Card Notes section (reproduced here in individual Gatherer rulings) provides guidance for fitting these cards into the existing rules structure.
Playtest cards use a modified version of game symbols, such as {T} and {W}. These modified symbols should be treated as the standard symbols during play.
