In the Star Wars universe, it's usually the case that shields can block energy weapons (blasters, lightsabers, lasers) but don't do much against physical objects (rocks, bullets, spacecraft). This is how they work in the new Battlefront game, where they protect against everything except explosives and slugthrowers.
In-game, the card for the personal shield powerup describes it as adapted droideka technology, and, notably, you can't fire your weapons while inside a personal shield. This may be for game balancing purposes, but it does raise the question: how can droidekas shoot through their own shields when no one else's energy weapons can? Are there any other examples of one-way shields in Star Wars? It's unlikely there's going to be much new canon material about this, so Legends answers are fine.