Draft Tampering is illegal.. but it happens and the AFL has consistently turned a blind eye to it ever since the Chalmers affair, even though worse offences have been committed since then. Luke Ball nominated for the draft, but refused to sit a medical examination for any club other than Collingwood - how that was not deemed to be draft tampering is entirely beyond me. The only draft tampering case that I can recall since Chalmers is Adelaide being prosecuted over the Tiprat contract - and the AFL was right to do so on that occasion.
No player can be traded against their will, and forced to enter into a contract with their new club. The only way a player can be forced to enter a contract with a club they don't want to be at is if they nominate for the draft. Should they choose to do so (either ND or PSD), and nominate terms, then the following applies:
There is surprisingly little in the AFL Player Rules about the trading of players. The inability of clubs to force players to sign with non-preferred clubs is probably a matter of Australian Law, rather than an AFL imposed thing. The draft is different, because the act of nomination explicitly states that players accept that they could be selected by any club and agree to be bound to the club which drafts them.
At the end of the day, there is virtually no chance of Dangerfield ending up at a 3rd club during the trade period. He may end up at a 3rd club if no trade is done and he nominates for the ND or PSD (as is his right). It is in the best interests of all 3 parties to see that a deal is done - Adelaide, Geelong, and Dangerfield. For that reason, I expect that a deal will be done. Adelaide will get less than Dangerfield's worth, Geelong will pay more than they're happy with, and Dangerfield will be wearing blue & white hoops in 2016.
What restrictions does the AFL place on contract terms?..