One of the biggest changes for me in the recent patch was the changes to runes.
The fact that two runes now spawn on the river every two minutes, one of which is a bounty rune, has made a huge difference to caster support play. The new bounty rune of itself provides gold and experience for hard-up supports which lack both of those things, but the key change is that, with two runes there is the opportunity for two heroes to run a bottle.
A bottle charge replenishes 135 health and 70 mana – equivalent to a tango and half a clarity. All three charges are therefore equivalent to a salve and 1.5 clarities. For free. Every two minutes.
Previously it was pretty unusual for me to get a bottle as a support – I had assumed that the mid hero would want one and I didn’t want to take their runes. With two runes available however I am finding it very possible to run a bottle as a caster support, and the sustain it offers is amazing.
With a bottle and arcane boots, I am genuinely struggling to get through my mana pool at times.
All of this means that rune control is extremely important in that appropriate warding and defending of runes can not only help your mid hero dominate the lane, but also give the side lane supports much more licence to spam their spells in the early game, potentially getting kills and winning the lane.
I have also seen organised attempts to get first blood at level 1 by the runes – something I’ve never encountered before.