Leech

Definition
When a player 'leeches' off another player, they receive a share of another player's experience (normally a much higher level) without actually killing any monsters (normally high-level monsters). This method of power-levelling is not always possible on a Ragnarok server, however, in Testimonial Midgard the party share rate is very high, so low-level players may "leech" off high-level players.

Power Levelling by Leeching
Normally a player will go to a high level dungeon and sit within range of party sharing while other player(s) fight monsters. This can be an extremely effective way of levelling up. However, many players consider leeching a "cheap" way of levelling up fast, and do not assist players requesting it.