I've noticed that there are quite a few items that give, at least, a +10 bonus to skills like Medicae. Do all of these bonueses stack with each other?

Example: An Apothecary with a diagnostor helmet (+10 Medicae), narthecium (+20 Medicae on Astartes patients), and a vivesection gage (+10 Medicae) is working on an Astartes patient. Does the Apothecary take all bonuses (+40 Medicae) or just the highest bonus (+20 Medicae)?

It seems to me like the bonuses stack but, being a life-long Dungeons and Dragons player (where bonuses are often not cumulative) i thought it best to ask.

Yes, all bonuses stack. Also remember that maximum bonus/penalty is +/-60

In case of a skill test, like Medicae, all modifiers apply, so they do stack.

Thanks guys. I appreciate it.

This is all correct.

I will add, skill improvement (for instance purchasing the medicae +10 advance) is not a bonus to the test. Skill improvements increase the testing threshold for the skill. Medicae is INT so a character with Medicae +10 must roll under INT+10 for all tests. It does not add a +10 bonus to the skill test.

Example

Medicae

INT 40

+20 test bonuses

Rolls a 56 (Needed to roll under 40+20)

Succeeds with zero Degrees of Success.

Example 2
Medicae +10
INT 40

+20 test bonuses
Rolls 56 (Needed to roll under 50+20)

Succeeds with one Degree of Success.

The Talented trait is an automatic +10 bonus to tests (not a skill increase).

I will add, skill improvement (for instance purchasing the medicae +10 advance) is not a bonus to the test. Skill improvements increase the testing threshold for the skill. Medicae is INT so a character with Medicae +10 must roll under INT+10 for all tests. It does not add a +10 bonus to the skill test.

This is true, it also makes it figuring out if you've hit your cap somewhat of a confusing mess.

Its just like any other game system out there. Skill advances are added to the skill's characteristic to determine the number you must roll under for success (jeeze, why couldn't I think of that when making my last post, I always come up with better ways to say things after the fact...). Test bonuses are seperate and apply once for each unique and individual test.

I will add, skill improvement (for instance purchasing the medicae +10 advance) is not a bonus to the test. Skill improvements increase the testing threshold for the skill. Medicae is INT so a character with Medicae +10 must roll under INT+10 for all tests. It does not add a +10 bonus to the skill test.

This is true, it also makes it figuring out if you've hit your cap somewhat of a confusing mess.

Deathwatch has so many rules to be honest I actually ignore the bonus cap rule and instead operate the overspill re-roll house rule.

Say someone ends up with needing a score of 118 to succeed because of bonus etc then the overspill rule is 96-100 is a fail. However the player then gets a 18% re-roll to succeed. The also ignore any GM capriciousness with rolling a critical fail. Unless of course they roll of 96-100 again.

I find this makes it simpler to work out what someone needs to roll.

Having a TN over 100 is pretty important for characters who rely on full-auto weapons to maximize their hits. Aside from that, not a bad idea but not very grimdark.

I don't fail 5% of the time when I try to do something easy. I do it almost all the time.

Bogi pours the cereal into his bowl. Then he reaches for his milk. As he pours the milk into the bowl bogi is only half-suprised as his breakfast bursts into flame in front of him, singing his eyebrows.