
The Grenade unlocks are similar, but because you are limited in how many grenades you can quickly get (one M67 Frag per life at the start), until you have them all unlocked you should use them whenever you get an opportunity. For both of these, you only need to kill enemies, which is after all what weapons are for. Weapon attachments are unlocked only by kills, and don’t benefit from the boosts. Weapon classes require you to use the weapon and gain points from kills, which do receive XP boosts. Even so, you should expect to see all of your favorite kits and vehicles fully unlocked by rank 50. Vehicles are dependent on both how much time you get to use them, and how skilled you are - especially, not dying and thus losing your ride. You can complete all kits as early as rank 25, but are likely to spend time in vehicles and may take until rank 30 or more to do that. Because your earned XP count for both the kit or vehicle you are operating and your overall rank, you are going to complete the unlocks for your favorite vehicles and kits relatively early in your career.

It is your advancement in kits and vehicles, and to a lesser degree weapon classes and attachment unlocks. It isn’t your overall rank, though, which is critical for game play. With five items each, the odds are good of getting at least one more boost, but I’ve had some which were all boosts. Rank 50 is the golden rank, literally - you get Gold Battlepacks at every rank starting here. Once you are above rank 10 you will start to get enough new Battlepacks to get more boosts. On the other hand, if you are playing to explore the map and try out things, and won’t earn many points during that game, the XP boosts are wasted. Double XP events are cumulative with the XP boosts, so saving the higher 100% and 200% boosts for those can be good - they give 4x and 6x XP respectively then.


But in your early career, you may not have quite so many to use, so choosing when to use them requires careful planning. You will get many of these in the course of the game, and will hit a point where using one every time you play will let you gain replacements before they expire. The biggest factor besides your skill in active play are the XP boosts. There are other games where your choice of actions can boost your rewards considerably, but for the most part, you can’t control those in Battlefield. Metallicat here, and first I’m just going to say that there is no big secret to unlocking items for kits, vehicles, and weapons in Battlefield 4.
