does drinking a potion cause an attack of opportunity?
No. Only moving out of the reach of a hostile creature provokes an opportunity attack, and even then only if it hasn't already used it's reaction for the round. And even that won't provoke an attack if the creature that is moving uses the Disengage action, teleports, or if the movement is forced.
Side question: With the thief ability 'fast hands' rogues can get at 3rd level, can rogues drink a potion just using a bonus action? Slightly off topic, can they apply a healers kit as a bonus action?
For me drinking a potion is a Full Round Action that draws an AOO. I know it is not RAW, but it is ridiculous to me for someone to try to drink a potion in the middle of a fight. If you are hit you drop the potion and it is destroyed. I just can't imagine fighting Mike Tyson (or anyone) and trying to drink a potion.
Noon wrote:
pend_collective wrote:
LordZeta wrote:
Reemer wrote:
Noon wrote:
LordZeta wrote:
it's crazy (coming from 3.5) how many attacks of opportunitys have been done away with. no 5 ft step, no attack of opp when casting in melee, drinking a potion, etc. trying to wrap my head around them all lol.
pend_collective wrote:
Saelorn wrote:
Reemer wrote:
To me, it depends on the size of the potion.
If it can be consumed in a swallow or two, no AoO.
If it is a 32oz monster drink, you suffer an AoO. 
Coredump00 wrote:
That kind of makes sense, the Intro to AoO is written in a pretty broad sense, then it only mentions leaving combat range. (which is really a poor choice from a 'reality' concept.) The intro would make more sense if accompanied with more AoO options. Or at least a framework for adjudicating them.