Historical clue formulations

• Take part in a D&D campaign, e.g. — 2021-03-28
• Be someone you're not — 2020-08-07
• Not be oneself? — 2019-12-26
• Not be oneself, but rather be one's elf? — 2019-10-11
• Be a wizard or an elf, say, in Dungeons & Dragons — 2009-06-15
• Not be oneself? — 2005-11-26
• Employ a therapeutic technique — 1999-06-27
• Simulate — 1999-03-27