How to tell which party members a skill affects

It is possible to determine if a support skill is multitarget or not by clicking on the skill in question and then mousing over the characters. If a skill is multitarget, it will connect the green bars with a cross like symbol (+). If a skill is single target it will not connect the bars.

Note that some skills do not just affect the selected character but also the user (regardless of rank). This is usually listed when holding the mouse on the skill. (for example, Battlefield Medicine can only be used in rank 3 and 4 but can be targeted to any rank but will also always heal the Plague Doctor as well).

Unfortunately not. The only way to tell is in battle, or by researching outside the game. I recommend the wiki.

While looking up the full list, I noticed some rules that apply for most abilities. If the ability does any of the following and does not say it affects the party, it is single target. Otherwise it is multi-target.

• Healing
• Stress Recovery
• Debuff/DoT removal
• Guarding

The exceptions are:

• The Houndsmaster's Cry Havoc hits the entire party
• The Plague Doctor's Emboldening Vapors hits a single target