I ran a session yesterday in which a player wanted to grapple enemies and pin them to the ground and noticed that there were no rules for grappling.
I house ruled this as:
Grappling
Cost: AP 2
Effect: Make an opposed Weapon Skill check. If you succeed, the enemy cannot take any actions until he is no longer grappled. On the grappled enemy's turn, he may spend 1 AP to make an opposed Strength or Weapon Skill check (grappled enemy's choice) with the grappler. If he succeeds, he is no longer grappled.
When you make a successful grapple with an opponent, you may spend 1AP to try and knock him Prone. This requires a successful Opposed Strength check at +10 for the grappler.
I know that it needs to be cleaned up, but I'm posting this from work at the moment, and will revise it when I get home. Hoping to see something official in the eratta.