In example dice at contracts directory, alice/bob should set permission to dice account for transferring EOS token from alice/bob to dice.
alice dice contract eosio.token contract
--------- ------------- -------------------
| set permission to dice | |
| | |
| offerbet(some eos) | |
|----------------------------->| transfer(alice->dice) |
| |------------------------>|
| | |
To play this game, alice/bob should grant privilege to dice for transferring EOS from alice/bob to dice.
Can alice/bob can transfer EOS to dice account directly and once dice can be triggered some action like fallback funciton in Ethereum?