The Witcher 3 Wild Hunt: Guide to Assassin King Radovid [Regicide]
Be careful because skipping this result is really very easy.
Guide Trophy / Objective "Regicide", take part in the assassination of King Radovid
To unlock this achievement you have to do a series of secondary missions long enough to trigger the secondary mission "Reasons of state" at the end of the game. It is during this mission that you will end up assassinating King Radovid.
The tricky part therefore lies in the perform during the game all the actions required to activate this particular mission. If you skip one of the NECESSARY side missions (those listed below and shown in the video) before going to the Isle of Mists you will not be able to kill the King and thus unlock the Trophy. This will also happen if you make a wrong dialogue choice during the "Absolutely Obvious" main mission for this be careful to always choose the first dialogue option at the end of this mission when speaking to Dijkstra and Philippa.
The missions to complete in order to play the "Reasons of State" mission are:
1. Redania's Most Wanted (minuto 0:05 del video)
2. An Eye for an Eye (minuto 0:49 del video)
3. A Matter of Life and Death (minuto 1:30 del video)
4. Now or Never (minuto 2:23 del video)
5. A Deadly Plot (minuto 3:22 del video)
6. Blindingly Obvious (minute 4:40 - always choose the first dialogue option by speaking to Dijkstra and Philippa)
7. Reason of State (minuto 7:10 del video)
Do these missions as soon as possible, watch the video showing what to do to start each of these missions