actually it's perfectly legal in mtg and quite commonIn Magic, it is considered colluding and highly illegal. I hope the next update they make to the rules take IDing out.
To quote mtg tournament rules:
"2.4 Conceding or Intentionally Drawing Games or Matches
If a game or match is not completed, players may concede or mutually agree to a draw in that game or match. A
match is considered complete once the result slip is filled out or, if match slips are not being used, a player leaves
the table after game play is finished. Until that point, either player may concede to or draw with the other, though
if the conceding player won a game in the match, the match must be reported as 2-1. Intentional draws are always
reported as 0-0-3."
Edit: pdf herehttp://wpn.wizards.com/sites/wpn/files/attachements/mtg_mtr_8apr16_ena.pdf
ID only exist in paper Magic. On MtGO, you cannot ID. Scott Larabee recently stated that if they had essentially a chess clock, they would remove IDs from paper magic as well.
My solution for IDs is simple- there are no draws. There must be a winner. To paraphrase Yoda- Draw not. Win or win not. There is no draw.