In short, Bolster is a PvP mechanic intended to close the gap between undergeared and better-equipped characters. It is applied whenever you enter a warzone or arena (or by using the Bolsterizer on the Imperial or Republic Fleet).

As of game update 5.5, any gear whose item rating is below 242 is Bolstered to (be equivalent to) 242.

Bolster Testing

Methodology

The parameters of our test are as follows:

no class buff

no stim

no utilities

no augments

tested Sorcerer DPS and healing disciplines

tested default Force-Mystic’s sets; the ratio of Critical Rating to Alacrity remained consistent between tiers

+41 Critical Rating crystals in main hand and offhand

all datacrons and companion bonuses.

Note: The Corruption discipline has a 3% passive increase to its damage reduction.

Note: Bolster seems to take account of augments, hence why our data shows that 248s benefit from Bolster.

Note: Full list of item modifications is given in the spreadsheet.

Analysis

Based on the data we’ve collected, we infer that Bolster grants stats according to your role.

Healers gain more Alacrity Rating and Critical Rating. Damage dealers gain Accuracy and more Power. Tanks gain Defense, Absorption Rating and Shield Rating, as well as extra Endurance.

Neither healers nor tanks gain Accuracy from Bolster.

Note that damage dealers gain Accuracy when Bolstered, regardless of their discipline. That is, DPS Sorcerers gain Accuracy, despite having no white damage attacks that benefit from Accuracy.

From our tests, we suspect that Bolster grants you a fixed amount of offensive stats based on your overall item rating. This means that you can adjust your tertiary stats as desired. For instance, if you want more Accuracy than Bolster provides, you can swap out gear or item modifications. Be aware that equipping gear and item modifications of mixed item ratings can have unpredictable results.

Interestingly, Bolster grants you bonus stats even if you have nothing equipped at all (see Table 1 below).