From Vanguard Wiki
A Strategy is the selection of Statements you make before you commence a diplomacy parley encounter. Although a player may have dozens of Statements in their deck, they are limited to using the Statements they laid out on their Strategy table before the parley commenced. It's like dealing yourself a hand of cards.
The number of cards you are able to place in your Strategy depends on your diplomacy skill level.
| Skill Level || Number of Statements
|1-? || 5
|?-? || 6
|?-? || 7
|?-? || 8
 Opening the Strategy Table
To access the Strategy table, go to the Abilities Book (or press "P") and select the Diplomacy tab. At the bottom, press the button marked "Strategy".
 Forming a Strategy
Drag Statements from your Abilities Book into the card spaces on your Strategy Table. Click "Strategy" again when you're done, and then close your Abilities Book.
 Changing Strategies
You cannot change the Statements in your Strategy after the parley has commenced.